Surface cleaning apparatus

ABSTRACT

A surface cleaning apparatus includes a heated vapor generator for generating steam and a supply tank for containing a supply of fluid. A liquid conduit that is in fluid communication with the supply tank is in heat exchange relationship with a vapor conduit that is in fluid communication with the heated vapor generator.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/921,463, filed Oct. 23, 2015, which is a continuation of U.S. patentapplication Ser. No. 12/328,003, filed Dec. 4, 2008, now abandoned,which is a divisional of U.S. patent application Ser. No. 10/710,776,filed Aug. 2, 2004, now U.S. Pat. No. 7,752,705, all of which areincorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

Upright extraction cleaning machines have been used for removing dirtfrom surfaces such as carpeting, upholstery, drapes and the like. Theknown extraction cleaning machines can be in the form of a canister-typeunit as disclosed in U.S. Pat. No. 5,237,720 to Blase et al. or anupright unit as disclosed in U.S. Pat. No. 5,500,977 to McAllise et al.and U.S. Pat. No. 4,559,665 to Fitzwater.

The state of the art for water extraction cleaning machines utilizes oneof two different technologies. First, water is mixed with a cleaningdetergent and the resulting solution is sprayed onto the surface to becleaned. The detergent includes chemical agents adapted to enhance thecleaning performance and dirt attraction of the cleaning solution. Thevacuum motor is used to create a source of suction for withdrawing thecleaning solution and entrapped dirt back into the cleaning machine.

A more recent development in the water extraction cleaning industry isthe use of steam as the cleaning agent. The cleaning machineincorporates a boiler or other means for generating steam. The steam ispumped to an applicator where it is brought into contact with thesurface being cleaned. The steam systems have the advantage of creatinga temperature which effectively kills a wide range of microbes,bacteria, microorganisms, and mites. However, the steam systems sufferfrom poor cleaning performance. Additionally, the high power requirementfor generating steam does not allow ample remaining power for running avacuum motor, so cleaning performance is further hindered. Conversely,conventional detergent cleaning systems are somewhat effective atcleaning surfaces, but could be made more effective by raising thetemperature of the cleaning solution to some point below the boilingpoint. There is an optimal temperature at which cleaning performance ismaximized without causing damage to carpets or setting stains. Thistemperature is around 150 degrees Fahrenheit.

The Chae et al. U.S. Pat. No. 5,502,872 discloses an electric vacuumcleaner having a steam discharge and cloth wiper. A water tank mountedon the handle dispenses water into an aspirator which atomizes the waterinto a stream of pressurized air from an impeller exhaust and then heatsthe atomized water to steam before discharging the steam/air mixtureonto a surface to be cleaned.

The Jones et al. U.S. Pat. No. 4,114,229 discloses a surface cleaningapparatus in which a cleaning fluid is heated in a conduit in a controlcasing and then sprayed onto a surface to be cleaned. A suction nozzlein a base unit removes dirty water from the surface.

The Parise et al. U.S. Pat. No. 4,046,989, and Putt, U.S. Pat. No.3,699,607, disclose floor-cleaning equipment in which a cleaning fluidis heated before it is sprayed onto a surface to be cleaned. Bothsystems appear to heat the cleaning fluid in a tank.

When heated cleaning fluid is applied to a surface that is at ambienttemperature, the cleaning fluid is cooled by the carpet, thus decreasingthe cleanability of the applied fluids. Heating the cleaning fluid to ahigher temperature to compensate fir the surface cooling may overcomethis problem, but with an increase in energy required for the operation.

Sometimes, one encounters spots on a carpet or other surface to becleaned that have a stain or other difficult area to clean whileconduction an ordinary cleaning process. Typically, the user must repeatthe extraction process in a particular spot with limited success.

DE 195 22 893, published 8 Feb. 1996, discloses a canister extractioncleaning machine in which a cleaning solution can be heated in a highspeed in line heater to a temperature below boiling or above boiling forapplication to a floor with a wand. This publication further disclosesin another embodiment a canister extraction cleaning machine that has asolution supply for application of unheated solution onto a surface tobe cleaned through a wand and further has a separate tank with a heaterfor heating water to steam. The separate tank is connected to the wandto deliver steam to the wand with or without cleaning solution.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a surface cleaning apparatusincludes a heated vapor generator adapted to heat fluid to approximately212° F. to generate steam, a supply tank for containing a supply offluid, a vapor nozzle configured to dispense steam to the surface to becleaned, a liquid spray nozzle configured to dispense liquid to asurface to be cleaned, a vapor conduit in fluid communication with theheated vapor generator and the vapor nozzle, and a liquid conduit influid communication with the supply tank and the liquid spray nozzle,wherein a portion of the liquid conduit is in heat exchange relationshipwith the vapor conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view of the extraction cleaning machine.

FIG. 2 is an exploded view of a base module of the extraction cleaningmachine shown in FIG. 1.

FIG. 3 is an exploded view of a base module and tank assembly of theextraction cleaning machine of FIG. 1.

FIG. 4 is an exploded view of a handle assembly and portions of the basemodule for the extraction cleaning machine of FIG. 1.

FIG. 5 is a partial sectional side view of the foot module of theextraction cleaning machine of FIG. 1.

FIG. 5A is an exploded view of a floating brush assembly for theextraction cleaning machine of FIG. 1.

FIG. 5B is a perspective view of an alternative brush assembly for theextraction cleaning machine of FIG. 1.

FIG. 6 is a partial sectional side view of the extraction cleaningmachine of FIG. 1 with the handle assembly in a tilted position.

FIG. 7 is a side sectional view of the pump and pump priming assembly ofthe extraction cleaning machine of FIG. 1 with a plunger in a firstposition.

FIG. 8 is a side sectional view of the pump and pump priming assembly ofthe extraction cleaning machine of FIG. 1 with a plunger in a secondposition.

FIG. 9 is a partial perspective view of the belt access door assembly ofthe extraction cleaning machine of FIG. 1.

FIG. 10 is a partial sectional view of the auto-mix valve of theextraction cleaning machine of FIG. 1 with a valve stem in a firstposition.

FIG. 11 is a partial view of the auto-mix valve of the extractioncleaning machine of FIG. 1 with a valve stem in a second position.

FIG. 12 is a partial side sectional view of a diverter valve with thevalve plate shown in a first position and in phantom for a secondposition for the extraction cleaning machine of FIG. 1.

FIG. 13 is a partial side view of the valve assembly of FIG. 12 with thevalve plate in the second position.

FIG. 14 is a sectional view of the air/water separator lid along line14-14 of FIG. 3.

FIG. 14A is a partial side view of a closure plate in three positionsrelative an air exit from the air/water separator lid of FIGS. 13 and14.

FIG. 14B is a partial sectional view taken along lines 14B-14B of FIG.14;

FIG. 15 is a sectional view of the air/water separator lid along line15-15 of FIG. 14.

FIG. 16 is a partial sectional view of the tank assembly and handleassembly of the extraction cleaning machine shown in FIG. 1.

FIG. 17 is a fluid flow diagram for the extraction cleaning machine ofFIG. 1.

FIG. 18 is an exploded view of the in-line heater of the extractioncleaning machine of FIG. 1.

FIG. 19 is a top view of the fluid flow indicator of the extractioncleaning machine of FIG. 1.

FIG. 20 is a side sectional view of the fluid flow indicator of FIG. 19.

FIG. 21 is a bottom perspective view of a drain plug of the base moduleand tank assembly of FIG. 3.

FIG. 22 is a top perspective view of the drain plug of the base moduleand tank assembly of FIG. 3 and illustrated in FIG. 21.

FIG. 23 is a side elevational view of a cleaning wand according to asecond embodiment of the present invention with a nozzle assembly shownin partial cross section.

FIG. 23A is a top plan view of a control knob 42 according to theinvention.

FIG. 23B is an enlarged view of a control valve illustrated in FIG. 23for controlling the flow of cleaning solution and heated vapor to asurface.

FIG. 24 is a side elevational view of a cleaning wand according to athird embodiment of the invention with a nozzle assembly illustrated inpartial cross section.

FIG. 25 is a side elevational view of an upright extraction cleaningmachine according to a fourth embodiment of the invention.

FIG. 25A is a schematic electrical diagram of an electrical circuit forcontrolling the power alternately to an electrical heater and to avacuum motor.

FIG. 26 is a side elevational view of an upright extraction cleaningmachine according to a fifth embodiment of the invention.

FIG. 27 is a side elevational view of an upright extraction cleaningmachine according to a sixth embodiment of the invention.

FIG. 28 is a partial sectional view of a liquid delivery nozzle assemblyaccording to a seventh embodiment of the invention.

FIG. 29 is a partial sectional view, like FIG. 26, of an uprightextraction cleaning machine according to an eighth embodiment of theinvention.

FIG. 30 is a partial sectional view, like FIG. 26, of an uprightextraction cleaning machine according to a ninth embodiment of theinvention.

FIG. 31 is a schematic view of an electrical system used in theembodiment of FIG. 30.

FIG. 32 is a schematic view of an alternative combined heated vaporgenerator and solution heater in accordance with the embodiment of FIGS.30 and 31.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings and to FIG. 1 in particular, an uprightextraction cleaning machine 12. The machine 12 is a portable surfacecleaning apparatus including a base module 14 adapted to roll across asurface to be cleaned and an upright handle assembly 16 pivotallymounted to a rear portion of the base module 14.

As best shown in FIGS. 1-3, the base module 14 includes a lower housingportion 15 and an upper housing portion 17, which together define aninterior for housing components and a well 730 for receiving a tankassembly 50. Further, a well 732 in the upper housing portion 17receives a detergent supply tank 870, as best shown in FIG. 3. The upperhousing portion 17 receives a transparent facing 19 for defining a firstworking air conduit 704 and a suction nozzle 34, which is disposed at afront portion of the base module 14 adjacent the surface being cleanedfor recovering fluid therefrom. The handle assembly 16 has a closed loopgrip 18 provided at the uppermost portion thereof and a combination hoseand cord wrap 20 that is adapted to support an accessory hose 22 and anelectrical cord (not shown) when either is not in use. A latch assembly21 is pivotally mounted to the rear portion of the base module 14adjacent the rotational union of the handle assembly 16 therewith forreleasably locking the handle assembly 16 in its upright position.

As shown in FIG. 2, the base module 14 houses a drive motor 196 that isconnected to a source of electricity by the electrical cord. A motorcompartment 500 within the base module 14 is a clamshell-shaped housingfor holding a motor assembly in place and preventing rotation thereof.The clamshell motor compartment 500 includes an upper half 502 and alower half 504. The upper half 502 is removable from the lower half 504,which is integral to the extraction cleaner base module 14. Thus, abottom wall of the lower half 504 is the bottom surface of theextraction cleaner base module 14. An arm 651 extends upwardly from themotor housing 500 in the base module 14 to support the flow indicator650, which is mounted to an upper end thereof. An opening 653 in theupper housing portion 17 receives the flow indicator 650 when thatportion is mounted to the lower housing portion 15.

The motor compartment 500 includes a large circular impeller fan housing510 and a smaller motor housing 512, further having a generally T-shapedcross section. The impeller fan housing 510 surrounds an inner housing41 defining a vacuum source 40, which is created preferably by animpeller (not shown) disposed within the housing 41. The housing 41includes a large aperture 516 for mounting a vacuum intake duct 530,which is sealed to the aperture 516 by a gasket 520. The vacuum intakeduct 530 connects the vacuum source 40 to an air/water separationchamber 750 (shown in FIGS. 3, 14, 14A, 14B and 15) in a lid 700 on thetank assembly 50, as well as the suction nozzle 34 on the front portionof the base module 14 and a suction nozzle (not shown) on a distal endof the accessory hose 22. The smaller end 512 includes a small aperture524 for receiving therethrough a motor drive shaft 198. A stretch belt204 is received on the motor drive shaft 198 outside of the clamshellmotor compartment 500. Further, an upper surface 520 of the motorcompartment 500 supports and secures an accessory hose intake duct 540partially defining a second working air conduit 706 (as shown best inFIGS. 12-14), which connects the suction nozzle on the distal end of theaccessory hose 22 to the vacuum source 40.

The drive shaft 198 of the drive motor 196 is connected to an interimdrive shaft 200 of a solution pump 202 by the stretch belt 204, which inturn, is connected to a rotatably mounted agitation brush 206 by atiming belt 208, as best illustrated in FIGS. 5 and 6. On the oppositeside of the motor 196, the motor drive shaft 198 supports the impeller(not shown) within the impeller housing 41, which provides the vacuumsource 40 and is mounted inside the housing 510 of the motor compartment500. With this configuration, a single drive motor 196 is adapted toprovide driving force for the impeller, the solution pump 202, and theagitation brush 206.

As best seen in FIGS. 2, 5, 5A, and 6, the rotatably mounted agitationbrush 206 is adapted for floor-responsive adjustment by a floating brushassembly 400 mounted within an agitation brush housing 26 disposedwithin a forward portion of the base module 14. The floating movement ofthe agitation brush 206 is a horizontally oriented arcuate path forreciprocation toward and outward of the agitation brush housing 26. Ends452 of an agitation brush shaft 206 are received in bearings 454, whichin turn, are press fit into inwardly extending bosses 456 to provide apair of opposed articulating arm members 458. Alternatively, stub shafts(not shown) can extend from the arm members 458 and the ends 452 can bereplaced with bearings similar to 454 for rotational installation of thebrush 206 on the arm members 458.

Each arm member 458 comprises a back plate 460 with a pivot pin 462provided at the rear of the plate 460. In addition, a laterallyextending belt guard 466 is preferably integrally formed with thearticulating arm 458. The belt guard 466, which extends laterallyinwardly enough to cover the timing belt 208, minimizes the lodging ofthreads and other foreign material in the timing belt 208 and protectsthe carpet or other surface positioned below the base assembly 14 fromthe rotating belt 208.

As best shown in FIGS. 5-6, 9, the timing belt 208 is reeved through apulley 216 mounted at one end of the brush 206 and a pulley 222 on theinterim drive shaft 200 of the pump 202, which includes a separatepulley 220 through which is reeved the stretch belt 204, which, in turn,extends around the drive shaft 198 of the motor 196. As best shown inFIGS. 7 and 9, the radius of the pulley 220 is larger than the radius ofthe pulley 222. Further, the pulley 220 has a convex cross section ofits periphery, whereby it is adapted to receive the smooth stretch belt204, while the pulley 222 has a toothed perimeter adapted forregistration with the teeth in the timing belt 208.

The pivot pins 462 of the arm member 458 are rotatably supported securedin a bearing (not shown) mount integrally formed with an internal wallof the agitation brush housing 26. Further, the pivot pins 462 are heldin the bearing by a support 478 on the non-belt side of the base module14 and the an arm 258 of the second belt access door 252 on the beltside of the base module, as best shown in FIG. 5A. Both the arm 258 andsupport 478 are secured to the agitation brush housing 26 by aconventional fastener (not shown) inserted through an aperture in eachpart. The arm members 458 are preferably limited in their downwardmovement relative to the agitation brush housing 26 by the length of thetiming belt 208 as well as the engagement of the brush guards 466 withthe arm 258 and the support 478. As the floating brush assembly 400extends further and further downwardly, the belt 208 will stretch andresist further downward movement. Eventually, the brush guards 466 oneach arm 458 will contact respectively the arm 258 and the support 478,which prevents any further downward movement.

With this floating agitation brush assembly 400, the cleaning machine 12according to the invention can almost instantaneously adapt to varyingcarpet naps or other inconsistencies on the surface being cleaned. Thearm members 458 also allow the rotating brush 206 to drop below thenormal floor plane, as shown in FIG. 6, to, for example, provide contactwith a bare floor.

As an alternative to the floating, rotatably mounted agitation brush206, a floating strip agitation brush 224 could be incorporated into thecleaning machine 12, as seen in FIG. 5B. In this embodiment, the stripbrush 224 comprises a linear brush portion 492 with bristles 494extending downwardly therefrom, and a pair of integrally molded arms 496having pivot pins 502, which can mount to the arm members 458 in placeof the pivot pins 462 supporting the agitation brush 206. With thisstructure, the strip brush 224 can move vertically in response tochanges to the carpet nap or other inconsistencies in the floor beingcleaned.

As shown in FIGS. 2, 5 and 6, an elevator assembly 410 comprises acentral support member 412 having at one end an L-shaped actuating arm418, and at another end, the ramped surface 414 on a forward arm 404opposed by a guide 416. Between the guide 416 and the ramped surface 414is mounted a spring assembly 406, which biases the assembly 410 rearwardtoward the handle assembly 16. The spring assembly 406 includes a spring436; a stop 426, which is attached to the base module 14 and throughwhich the forward arm 404 travels; and a flange 428, which is integralwith the forward arm 404. The spring 436 is held between the flange 428and stop 426, and biases the assembly 410 rearward relative the stop 426through force on the flange 428.

The arm 418 extends from within the base module 14 where it is mounted,through an aperture 402, towards the handle assembly 16. The actuatingarm 418 is forced horizontally forward when the rotatably mounted handle16 on the base module 14 is put in the upright position, which forces anupper portion 422 of the actuating arm 418 in a horizontal and forwarddirection. More specifically, as shown in FIG. 5, a curved surface 424on the handle assembly 16 strikes a rounded distal end 420 of theL-shaped actuating arm 418 when the handle assembly 16 is put in itsstorage or non-use position. When the handle assembly 16 is pivotedrearwardly for use, as shown in FIG. 6, the curved surface 424 shiftsrearwardly and the spring-biased elevator assembly 410 follows, with end420 riding the curved surface 424, until the elevator assembly 410reaches a rearward, rest position.

Thus, forward movement of the actuating arm 418 forces the supportmember 410 and ramped surface 414 forward, wherein the ramped surface414 contacts the underside of the brush guards 466 on each arm 458,thereby raising the floating brush assembly 400 as the elevator assembly410 moves from a rearward position to a forward position in the basemodule 14. That is, as the ramped surface 414 moves towards the front ofthe base module 14, the agitation brush assembly 400 slowly rises as thebrush guards 466 ride the ramped surfaces 414. Such a constructioneliminates the need for a manual arm for lowering and raising theagitation brush assembly 400 for storage or use of the accessory hose22, thereby eliminating risks of damage to the brush assembly andprotecting the carpet from the agitation brush assembly 400 restingthereon. When the handle 16 is moved to the in-use position, the springassembly biases the elevator assembly to its normal, rearward position.

As seen best in FIGS. 1 and 4, the base module 14 is supported at therear portion thereof by a pair of opposed rear wheels 552. The handleassembly 16 includes a U-shaped lower portion 560 having opposed arms562 and 564 including cylindrical bearings 578 for mounting the handleassembly 16 to the base module 14 and supporting axles 554 on a commonaxis for rotatably mounting the wheels 552 to the extraction cleanerbase module 14. More particularly, the handle assembly 16 tapers fromits wide, lower portion 560 to a thinner handle portion 570, having athin handgrip portion 572, including the closed loop grip 18 at itsuppermost end, by which the user moves the extraction cleaner. Thebearing 578 include a central circumferential groove 576 for receivingarcuate portions 588, 589 of the base module 14 whereby rotation of thehandle assembly 16 is facilitated.

The handle assembly 16 further comprises a front portion 580 and a rearportion 582 defining a substantially hollow interior supported bymultiple ribs 558. Mounts 584, disposed radially on the interior of thefront and rear portions 580 and 582 support an in-line heater 54, aswill be described in detail below. The substantially flat front portion580 is secured to the mated rear portion 582 by conventional fasteners,such as screws. The rear portion 582 further includes the combinedaccessory hose and electrical cord mount 20.

Returning to the lower portion 560, the arms 562, 564 comprise portionsof both the front portion 580 and the rear portion 582. When theassembly 16 is secured together, these arms 562, 564 pivot about thebearing 578 integrally formed with the arms 562, 564. The bearings 578,in turn, receive axles 554, on each side, respectively, for mountingwheels 552. The axles 554 extend through the wheels 552, apertures 586through the rear portion 582 of the lower arms 562, 564, and thebearings 578 integrally formed with the arms 562, 564. The axles 554,556 are secured by large diameter axle mounting clips 594, disposed,when installed, adjacent the bearings 578 and within the base module 14.A side edge 598 of the extraction cleaner base module 14 includes anarcuate surface 588 to accommodate the handle bearings 578 secured oninside portions of each arm 562, 564 of the rear portion 582.

Once the handle assembly 16 is mounted to each base module 14, with theaxles 554 secured by the mounting clips 594, the extraction cleanerupper housing portion 17 is secured to the lower housing portion 15. Theupper housing portion 17 also has an arcuate surface 589 formed in aside thereof for accommodating and securing the integral bearings 578 ofthe arms 562, 564. More specifically, the arcuate surfaces 588, 589 ofthe side walls of the housings 15, 17 are received in the centralcircumferential groove 576 formed in the circumference of each integralbearing 578. Thus, when the base module 14 is formed of the housings 15,17, the bearings 578 of the arms 562 are secured therebetween such thatthey can only rotate between an upright, stored position and an in-useposition and the wheels are mounted to axles 554,556 received throughapertures in the bearings 578 and secured by mounting clips 594.

The concentric wheel axle and handle pivot transfers all the force onthe handle assembly 16 to the wheels 552 to keep downward force on thesuction nozzle 34 constant. Further, the tank assembly 50, as shown inFIG. 3, center of gravity is close to the wheel center so that changingtank volume does not alter the downward force on the suction nozzle 34and allows the weight of the tank assembly 50 to be carried on thewheels 552 fairly evenly. Also, the handle assembly 16 supports verylittle weight and therefore keeps the weight that the user feels throughthe handle assembly 16 to a minimum. This creates an upright extractioncleaning machine 12 that is easy to use and less tiring for theoperator.

The handle assembly 16 is releasably locked against rotation from itsupright position by a latch assembly 21, which is pivotally mounted tothe rear portion of the base module 14 adjacent the rotational union oflower leg 564. The latch assembly 21 includes an upright lower portionwhich is pivotally mounted to the base module 14 at a rear comer thereofand an upper portion which extends upwardly and rearwardly of the lowerportion. A molded-in spring arm extends rearwardly from the lowerportion of the latch assembly 21 and bears against a rear portion of thebase module 14 to bias the lower portion forwardly and against the rearportion of the lower leg 564. The upper end of the lower portion of thelatch assembly 21 forms a horizontal latching surface which bearsagainst the rear portion of the lower leg 564 and engages projectionsthereon to lock the handle in the upright position in a conventionalfashion. Thus, as the handle assembly 16 is pivoted upright, the rearportion of the lower leg 564 rides along the horizontal latching surfaceuntil the edge catches the projection on the rear portion of the lowerleg 564, at which point the handle assembly 16 is locked upwardly. Torelease the latch assembly 21, the user pushes the step downwardly andagainst the bias of the molded-in spring to release the horizontallatching surface from the projection. The latching mechanism isconventional and forms no part of the invention of this application. Anyconventional latching mechanism can be used with the handle and basemodule in the invention.

The tank assembly 50 is removably supported on the rear of the basemodule 14 and defines both a fluid supply tank and a fluid recovery tanktherein via a flexible bladder 120 separating a fluid supply chamber 49from a recovery chamber 48. An air/water separator lid 700 seals the topof the tank assembly 50, which includes a valve mechanism 80 on a bottomportion for controlling the flow of cleaning solution fluid from thefluid supply chamber 49. The base module 14 includes a valve seat 88complementary to the valve mechanism 80, and the bottom portion of thetank assembly 50 and the valve seat 88 are substantially complementaryto one another so that the upwardly extending valve seat 88 issubstantially surrounded by and received in the bottom of the tankassembly, as will be described further below.

The lid 700 is secured to the tank assembly 50 by a rotatable handle790, as best shown in FIG. 16, which can be moved between a storageposition, in which the tank 50 is sealed by the lid 700 and the handle790 is disposed rearwardly horizontal (as shown in solid lines); atransport position, in which the tank 50 is sealed and the handle 790extends vertically upward (shown in phantom lines) for ease in carryingby the user; and a service position, in which the lid 700 can be removedfrom the tank assembly 50 and the handle 790 is disposed forwardly at anacute angle relative the lid (shown in dashed lines). The U-shaped tankhandle 790 rotates about a pivot 792 projecting from a side of the lid700. The pivot 792 is received in a bushing 794 disposed centrally in acircular mounting portion 796 at the ends of the handle 790. An arcuatewall 798 extending transversely from the mounting portion 796, integraltherewith, and having an opening 788 surrounds the bushing 794. When thehandle 790 is rotated about the pivot on the lid, an inside surface 784of the wall 798 engages a tab 786 extending transversely from an upperlip 782 of the tank assembly 50 for locking the lid 700 to the tankassembly. The surface 784 of the wall 798 engages the tab 786 when thehandle 790 is in either the storage or transport position. When in theservice position, the tab 786 is aligned with the opening 788 in thewall 798, whereupon the lid 700 can be removed from the tank assembly50.

As best shown in FIGS. 3, 14, 15, a flexible bladder 120, which is usedas a fluid supply tank, is mounted inside the rigid tank assembly 50.Thus, the tank assembly 50 is divided into a recovery tank and a fluidsupply tank defined as two fluid chambers separated by the bladder 120:a fluid supply chamber 49, comprising the interior of the bladder 120,and a fluid recovery chamber 48, comprising the volume between theflexible bladder 120 and the rigid walls of the tank housing 46. Thebladder 120 is molded from a pliable thermoplastic material and iscollapsible when empty to accommodate recovered fluid in the volumebetween the bladder 120 and the tank housing 46. Initially, the bladder120 is full of water or cleaning solution and occupies the vast majorityof the volume within the tank housing 46. As the user sprays thecleaning solution onto the surface to be cleaned, the volume of fluid inthe bladder 120 is reduced corresponding to the volume of solutionsprayed on the surface. During suction, recovered dirt and water arereceived in the tank housing 46 in the volume between the bladder 120and the tank housing 46. The volume available in the bladder 120 due toapplication of the cleaning solution is made available to recoveredfluid by the pressure of the recovered fluid collapsing the bladder 120,thereby forcing air out of the bladder 120. Because recovery of the usedcleaning solution is always less than 100% of the solution applied,there will always be ample room inside the tank housing 46 once thecleaning solution has been applied to the surface.

The bladder 120 is disposed within the tank assembly 50 between a bottomsurface 860 of the rigid tank housing 46 and a snap-in baffle plate 800,which will be explained in further detail below. An aperture 824 in thebaffle plate 800 has a diameter approximately matching that of a smalldiameter end 125 of a funnel-shaped filling spout 124 of the bladder120. Further, an upstanding collar 828 surrounds the aperture 824. Acylindrical shroud 770, as best shown in FIG. 17, is mounted on theinside of the air/water separator lid 700 and extends downwardlytherefrom to capture the filling spout 124. Thus, the increasingdiameter outside surface of the funnel-shaped filling spout 124 isretained in the aperture 824 and supported by the collar 828, therebyholding the flexible bladder 120 in an upright position in the tankhousing 46 between the bottom surface 860 and the baffle plate 800therein. As space between the upstanding collar 828 and the downwardlyextending shroud 770 defines a fluid passageway between the fluid supplychamber 49 and the recovery chamber 48, whereby the fluid supply chamber49 and the recovery chamber 48 maintain the same pressure, negative orotherwise.

The flexible bladder 120 includes an outlet 130 disposed in a lowercorner of the flexible bladder 120. The outlet 130 is mated with anoutlet aperture 862, as best viewed in FIG. 16, in the bottom surface860 of the rigid outer shell for supplying fluid to a fluid applicationsystem 950 and securing the bladder 120 to the rigid bottom surface 860of the tank housing 46.

The funnel-shaped filling spout 124 of the bladder 120 facilitatesfilling the bladder 120 and equalizing air pressure between the fluidsupply chamber 49 and recovery chamber 48. The filling spout 124 isalways open, so as to vent air from the bladder 120 as it collapses involume and the usable volume within the rigid outer walls of the tankhousing 46 expands in volume. Further, the open filling spout 124ensures that both chambers 48, 49 are at substantially the sameatmospheric pressure, which is preferably negative relative to standardatmospheric pressure because of the communication of the vacuum source40 to the tank assembly 50 via the air/water separator lid 700, as willbe explained further below. The volume of the bladder 120 is preferablyone gallon.

As best shown in FIG. 17, the valve mechanism 80 is provided within theoutlet aperture 862 through the bottom surface 860 of the tank housing46 and the aligned outlet 130 in the bladder 120 for controlling theflow of cleaning solution fluid from the fluid supply chamber 49. Thevalve mechanism 80 comprises a valve member (not shown) mounted withinthe aligned aperture 862 and outlet 130, which together are selectivelycovered by the valve member to enable or prevent the flow of fluid tothe fluid application system 950.

The base module 14 includes a valve seat 88, shown best in FIG. 17, thathas a fluid reservoir 90 adapted to receive fluid through the fluidaperture 862 and conduct this fluid to one end of the conduit 140, theother end being mounted to a clean water inlet 332 of a mixing valveassembly 310. The bottom wall 860 of the tank housing 46 and the valveseat 88 are substantially complementary to one another so that theupwardly extending valve seat 88 is substantially surrounded by andreceived in the bottom wall 860. A projection 94 is provided in thefluid reservoir 90 and is adapted to contact a head of a shaft of thevalve member (not shown). A spring received on the shaft of the valvemember is adapted to bias the valve member into the closed positionthereby preventing the flow of fluid through the fluid apertures. Whenthe tank housing 46 is seated on the base module 14, the head of thevalve member contacts the projection 94 and deflects the valve upwardlythereby permitting the flow of fluid around the valve, through the fluidapertures into the fluid reservoir 90 of the valve seat 88, and to thefluid application system 950. A gasket 81 seals the junction between thevalve mechanism 80 and the seat 88. When the tank housing 46 is removedfrom the base module 14, the projection 94 is removed from contact withthe head 96 of valve member. Therefore, the spring biases the valvedownwardly into the closed position thereby preventing the flow of fluidthrough the fluid aperture 862 to the fluid application system 950.

The fluid application system 950 conducts fluid from the fluid supplychamber 49 to fluid dispensing nozzles 100, which are mounted in thebrush housing 26 of the base module 14, and a fluid dispensing nozzle(not shown), which is mounted on an accessory cleaning tool (not shown),as best illustrated in FIG. 17. From the fluid supply chamber 49, cleanwater is conducted through conduit 140 to an inlet 332 to the mixingvalve assembly 310, which also includes a detergent inlet 336 that isfluidly connected to a detergent supply tank 870 by a conduit 314. Mixeddetergent and clean water form a solution that exits the mixing valveassembly 310 via an outlet 340, which is fluidly connected by a conduit142 to a pump priming system 280 disposed adjacent the pump 202. Aninlet port 282 for the pump priming system 280 is connected to theconduit 142, and pressurized fluid is expelled from the pump 202 througha pump outlet port 283, which is fluidly connected via a conduit 146 toa T-connector 150. The T-connector 150 supplies pressurized fluid toboth the accessory tool (not shown) and the heater 54 via conduits 148,138, respectively. The conduit 148 includes a grip valve 132 by whichthe user can manually displace a valve member, thereby enabling the flowof non-heated, pressurized fluid to the spray tip on the accessory tool.

The conduit 138 includes a trigger valve 134 having a displaceable valvemember that can be actuated by a trigger assembly 430, as best shown inFIG. 4, for selectively supplying the in-line heater 54 with pressurizedcleaning solution. The trigger assembly 430 includes a switch 432mounted conveniently within the closed loop grip 18 of the uprighthandle assembly 16, through which the user can depress the switch foractuating a manual link 434 for displacing the valve member in thetrigger valve 134, thereby allowing fluid to flow to the inlet port 72of the in-line heater 54.

Heated while passing through the heater 54, the fluid exits the in-lineheater 54 via an outlet port 74, which is fluidly connected via aconduit 136 to an inlet 652 for a flow indicator 650. An outlet 654 forthe flow indicator is fluidly connected to a T-connector 156 via aconduit 134. The T-connector 156 supplies fluid dispensing nozzles 100,which are mounted in the brush housing 26 of the base module 14, andsupplied with heating cleaning solution via conduits 126, 128.

A detergent supply tank 870, as best illustrated in FIG. 3, is receivedwithin a well formed in the upper housing 19 of the base module 14. Thesupply tank 870 includes a top surface 872 shaped complimentary to theexterior of the upper housing 17. A bottom surface 874 of the supplytank 870, as best shown in FIG. 17, includes an aperture 876 surroundedby a threaded spout 878, which receives a mated threaded cap 880 havinga valve mechanism 882 therethrough. The valve mechanism 882 will not bedescribed here as its structure and function mimics that valve mechanism80 described above for the tank assembly 50, as it too seats on aprojection 94 in a valve seat 318 for displacing the valve mechanism882. The valve seat 318 of the mixing valve assembly 310 includes afluid reservoir 320 for receiving and conducting fluid to one end of anL-shaped conduit 314, the other end being mounted to a detergent inlet336 of the mixing valve assembly 310. The threaded cap 880 also includesan air return conduit 890 mounted therethrough for equalizing thepressure inside the detergent supply tank 870 with the outsideatmosphere.

The mixing valve assembly 310 is positioned intermediate the tankassembly 50 and the solution pump 202. Preferably, the mixing valve 310is a variable mixing valve to accommodate differing mixtures ofdetergent and clean water. As seen in FIGS. 10, 11 and 17, the variablemixing valve 310 comprises a valve body 330 having a clean water inlet332 that is fluidly connected to the fluid supply chamber 49 and adetergent inlet 336 that is fluidly connected to a detergent supply tank870 by the valve seat 318 and, via the fluid reservoir 320, the L-shapedconduit 314. The mixed solution outlet 340 is also formed on the valvebody 330 and is adapted to conduct the clean water and detergentmixture, i.e., the cleaning solution, from the mixing valve 310 to afluidly connected pump priming system 280 adjacent the inlet of the pump202.

The valve assembly 310 includes an end cap 344 mounting a coaxialplunger 350 in a central body portion 346. The end cap 344 partiallyreceives a thread 372 of a knob 374 such that the plunger 350 can beraised or lowered in the valve body 346 when the knob 374 is turned.

The plunger 350 includes an annular groove 356 formed in a distal end276 thereof. The groove 356 is received within an O-ring 358. The distalend 276 and O-ring 358 are adapted to create a fluid seal inside thecircular valve body 346 when the plunger 50 is in its lowermost portion,as shown in FIG. 11, and define a mixing chamber 360 when the plunger350 is raised from its lowermost position, as shown in FIG. 10.

The distal end 276 of the plunger 350 further includes a tapered groove364, which is tapered so that the groove has a greater cross-sectionalarea immediately adjacent the head end 276 than it does a distancespaced upwardly therefrom. The tapered groove is positioned in thedetergent inlet 336 opening to control the flow of detergenttherethrough. That is, the tapered groove 364 accommodates varying flowrates of detergent from the detergent supply 870, through the conduit318, and through the detergent inlet 336 into the valve body 346. Thelower the plunger 350 is seated in the inlet 336, the less the area ofexposure of the tapered groove 364 in the valve body 346, therebylimiting the flow of detergent thereto.

The control knob 374 is mounted on an outside wall of the upper housingof the extraction cleaner for controlling the water to detergent ratioin the cleaning solution delivered to the fluid application system 950.The control knob 374 is mounted adjacent the end cap 344 and includes athread 372 that is received in a groove 380 of the end cap 344, so thatturning the knob 374 lowers or raises the plunger 350 in the valve body346. In a first position shown in FIG. 10, with the plunger 350 extendedupwardly from the valve body 346, the maximum cross-sectional area ofthe tapered groove 364 is exposed to define an inlet aperture 382 intothe valve body 346. Therefore, the maximum amount of detergent will bedrawn into the valve body 346 to mix with clean water supplied via inlet332, and ultimately discharged to the pump assembly 280 and fluiddispensing nozzles 100. The other extreme position of the plunger 350lowers the tapered groove 364 from the mixing chamber 360 completely soif there is no aperture 382 and thus no fluid flow communication betweenthe detergent inlet 336 and the valve body 346. Therefore, only waterwill be directed to the pump assembly 280 and spray tips.

As should be evident, rotation of the threaded knob 374 will provide aninfinite number of detergent-to-water mixing ratios between the twoextremes described above. In the preferred embodiment, however, thehousing adjacent the knob 374 is marked with three concentrationindicators: The first indicator is a water only or “rinse” position;second, a maximum detergent-to-water mixing ratio where the taperedgroove 364 is fully exposed in the valve body 346; or third, a standardmixing ratio approximately half way between the extremes describedpreviously. Of course, any variation of the indicated concentrationpositions can be employed by simply rotating the knob 374 to a positionbetween any two indicated positions. The extreme positions are definedby the shape of the length of the thread 372, which includes oppositeends defining a pair of extreme positions for limiting the rotation ofthe knob 374 relative the cap 344.

In use, the knob 374 is intended to be positioned at the standard mixingratio position for the vast majority of cleaning operations. When ahigh-traffic or heavily stained area is encountered, the knob 374 can berotated to the maximum detergent position. If a clean-water rinsingoperation is desired, then the knob 374 can be rotated to the water onlyposition.

As best illustrated in FIG. 17, the mix of detergent and water isdelivered via conduit 142 to the inlet port 282 for the pump primingsystem 280, which is disposed adjacent an inlet nose 288 of the pump202. Thus, in operation, the drive motor 196 is activated, therebyimparting rotation through the drive shaft 198 to the interim driveshaft 200, and the pump 202 is primed, as will be explained below.Rotation of the interim drive shaft 200 causes the pump 202 topressurize the fluid received from the fluid supply chamber 49, via themixing valve assembly 310 and priming assembly 280. Further, rotation ofthe interim drive shaft 200 causes the agitation brush 206 to rotate.Pressurized fluid flowing from a pump outlet port 283 is conducted tothe inline heater 54, a flow indicator 650, and then a plurality ofconventional fluid dispensing nozzles 100 provided near the front of thebase module 14 adjacent the agitation brush 206. The pressurizedcleaning solution sprays down onto the surface to be cleaned in afan-shaped pattern extending substantially the entire width of the basemodule 14. A fluid outlet port 74 of the in-line heater 54 is alsofluidly connected to a conduit 144, which is integrated into theaccessory hose 22. Fluid flows through the conduit 144 to the accessoryhose cleaning tool (not shown) provided at the terminal end of the hose22. With this configuration, pressurized cleaning solution is availableon demand for both the accessory cleaning tool and the fluid dispensingnozzles 100.

Referring to FIGS. 2, 5 and 6, the drive shaft 198 of the drive motor196 is interconnected to the interim drive shaft 200 of the centrifugalsolution pump 202 by the stretch belt 204, which allows dry, high speedoperation and operates as a clutch during brush roll jam conditions. Theinterim pump shaft 200 is interconnected to the rotatably mountedagitation brush 206 by the timing belt 208, which allows a slower, hightorque wet operation.

The interim pump drive shaft 200 functions as an interim drive providinga step down from the drive shaft 198 to the stretch belt 204 and thetiming belt 208 to the agitation brush 206. Because of the step downstructure, the drive motor 196 can be a high-efficiency, high-speedmotor (30,000 plus rpm), which is stepped down at the interim drive pumpshaft (approximately 12,000 rpm), and further stepped down at theagitation brush 206 (approximately 3,500 rpm).

The pump shaft 200 includes the pair of coaxial spaced-apart pulleys220, 222, as best seen in FIGS. 2, 8-9, for receiving each respectivebelt 204, 208, with a radially extending baffle 218 disposed between thepulleys so that the inwardly disposed stretch belt 204 is insulated fromthe wet environment in which the outwardly disposed timing belt 208operates to drive the agitation brush 206. A barrier coplanar with theradial baffle 218 insulates the environments from each other as formedby the juncture of a pair of belt access doors 250, 252, as will bedescribed below. The stretch belt 204 also functions as a clutch whenthe agitation brush 206 is jammed. Because the agitation brush 206 isconnected to the interim pump drive shaft, and the interim pump driveshaft 200 is connected to the motor drive shaft 198, there must be somemechanism to provide relief to the motor 196 when the agitation brush206 is jammed. This relief occurs at the drive shaft 198, which willturn inside the stretch belt 204 without rotating the stretch belt 204when the interim pump shaft 200 stalls due to an agitation brush 206jam.

As best shown in FIGS. 5-9, the timing belt 208 is structurally walledoff from the stretch belt 204 by the barrier defined in part by thefirst belt access door 250, second access door 252, and the baffle 218.Removing the first belt access door 250 provides access to the timingbelt 208 connecting the pump drive shaft 202 and the agitation brush206. Access to the stretch belt 204 connecting the motor drive shaft 198to the pump drive shaft 202 is provided only when the second belt accessdoor 252, disposed within a brush housing 26, is removed. As illustratedin FIG. 2, the first belt access door 250, having a substantiallyL-shaped cross-section, includes a substantially vertical portion 266and an angular, but substantially horizontal portion 264. As best shownin FIG. 9, the second belt access door 252 is rectangular, including anarcuate groove 254 in a front portion of a top surface 256 and atransversely extending arm 258 in a rear portion of the top surface. Thearm 258 secures the second door 252 in place in the brush housing 26 andsupports the pivot pin 462 on the pivot arm 460 of the floating brushassembly, as best shown in FIG. 5A.

More specifically, as shown in FIG. 2, the substantially verticalportion 266 of the first door 250 includes sides 240 that are receivedin a mated recess 242 surrounding an access aperture 236. Further, thefirst door 250 includes a depending flange 234 mounted to and spacedapart from a back portion of the door 250 and extending downwardlyparallel to the door 250 and further including an arcuate groove 244 ina lower end. Each side of the substantially horizontal portion 264includes a flexible tab 226 on each side that is received in arespective slot 228 disposed on the substantially horizontal face 222 ofthe upper housing 17 at each end of the access aperture 236 thatreceives the first belt access door 250. Thus, as the first belt accessdoor 250 is slid into place, the depending flange 234 extends behind theupper housing 17 defining the access aperture 236, the sides arereceived in grooves 242 in the upper housing 17 surrounding accessaperture 236, and the tabs 226 engage the slots 228 formed on thesubstantially horizontal portion 248 of the housing, whereby the firstaccess door 250 is secured in place. The first access door 250 can beremoved from the aperture 236 by flexing the tabs 226 inwardly torelease them from their receiving slots 228. As shown in FIG. 9, theinner depending flange 234, including groove 244, mates with theradially extending baffle 218 between the pulleys 220, 222 on the shaft200 and the arcuate groove 254 in the arm 258 of the second belt accessdoor 252 to separate the motor/pump stretch belt 204 from thepump/agitator timing belt 208.

The pump priming system 280 is disposed adjacent the pump inlet nose288, and draws from the fluid supply chamber 49 and the detergent tank870. The fluid supply chamber 49 is under negative pressure because itis in fluid communication with the recovery chamber 48 and the vacuumsource. Once primed, the pump 202 draws solution from the mixing valveassembly 310, and delivers the mixture to a spray tip 100 or anaccessory tool 44 for spraying on the surface to be cleaned. When thepump 202 stops, the solution in the supply conduit is drawn into thelow-pressure fluid supply chamber 49 and away from the pump 202. Acentrifugal pump is incapable of developing sufficient pressure to primeitself by overcoming the negative tank pressure.

With reference to FIG. 7, a pump priming assembly 280 as describedherein overcomes this problem. The pump-priming assembly 280, includes apriming chamber 260 for flooding the inlet nose 288 of the pump 202, aninlet port 282 for the chamber 260 that is fluidly connected to the nose288 of the pump 202, and a pump outlet port 283. A vacuum port 284 isfluidly connected to the vacuum source 40, or a portion of the recoverychamber 48 that is in fluid communication with the vacuum source 40.

The pump-priming assembly 280 also includes a hollow valve body 298having a plunger chamber 286 and a valve chamber 292. A valved opening295 joins the valve chamber 292 and the priming chamber 260. An outletopening 291 joins the valve chamber 292 and the plunger chamber 286.Also, an aperture 294 is formed at an upper inside portion of the valvebody 298 to fluidly connect the valve body 298 and the outlet 284. Anelongate buoyant plunger 290 having a top portion 297 at one end and arubber umbrella valve 296 at the other is received for reciprocalmovement inside the valve body 298. More specifically, the umbrellavalve 296 reciprocates between the valved opening 295 and the outletopening 291 and within the valve chamber 292. Thus, the plunger chamber286 substantially houses the elongate plunger 290, while the valvechamber 292 houses the umbrella valve 296, which is coaxially attachedto the elongate plunger 290 for reciprocal axial movement therewith.

In operation, the pump 202 will be primed with fluid from the fluidsupply chamber 49 by activating the pump 202 and the vacuum motor 196,which will exert negative pressure on the vacuum outlet 284, therebydrawing any air out of the priming chamber 260 and plunger chamber 286,and further overcoming the negative pressure exerted on the fluid in theconduits 140, 142 connecting the fluid supply chamber 49 to the pump202. The air will be drawn through the valve body 298 into the vacuumimpeller fan housing 510. Preferably, the weight and dimension of theplunger 290 is coordinated with the amount of negative air pressureapplied to the pump priming assembly 280 from the vacuum source 40 sothat the negative air pressure applied to the plunger chamber 286 isinsufficient by itself to draw the plunger 290 upwardly and seal theoutlet opening 291.

As the vacuum motor operates to draw the air from the system, fluidfills the chamber 260 and enters the chambers 292, 286. Eventually, thefluid level will fill the valve chamber 292 and rise inside the plungerchamber 286, pushing the plunger 290 upwardly causing the umbrella valve296 to seal the outlet opening 291, thereby preventing water from risingfurther in the plunger chamber 286 and being sucked into the vacuumsource 40. Because the pump nose 288 is submersed at this point, waterenters the pump 202 and primes it. As the pump 202 sucks water from thepriming chamber 260, the plunger 290 is drawn downward in the plungerchamber 286, and the umbrella valve 296 descends therewith in the valvechamber 292 to activate a seal in the opposite direction, as theumbrella valve 296 seats in the valved opening 295. The reverse sealprevents air from being sucked into the priming chamber 260 from thefluidly connected chambers 292, 286. This cycle repeats each time atrigger 432 in the closed loop handle 18 is activated or the unit ispowered off and on again. Once the reverse seal has been established,the chamber 260 should remain filled, the nose 288 of the pump 202flooded, and, thus, the pump 202 sufficiently primed for normaloperation.

From the pump 202, the pressurized fluid flows through a conduit 146 toa T-connector 150 for supplying both floor nozzles 100 and an accessorytool 44. The T-connector 150 includes outlets 152, 154 for supplyingboth the in-line block heater 54, and a floor spray nozzle 64, or anaccessory cleaning tool 44, respectively. Specifically, the first outlet152 of the T-connector 150 is connected to fluid conduit 148 that isadapted to supply non-heated and pressurized cleaning solution to aspray nozzle (not shown) on an accessory cleaning tool (not shown)mounted at the terminal end of the accessory hose 22. The second outlet154 is fluidly connected via a conduit 138 to the in-line block heater54, shown best in FIG. 18.

The in-line block heater 54 receives pressurized cleaning solution fromthe pump 202, via the T-connector 150, and further has a heating element56 that is electrically connected to a source of electricity (notshown). As shown in FIG. 18, the heater 54 includes an aluminum body 84having an inlet port 72, an outlet port 74, a heating element 56disposed within the aluminum body 84, and a serpentine channel 78 formedin a top face 76 of the block heater 54. A cover 79, via a gasket 70seals the top face 76, and thus the channel 78, and fasteners 86. Theheating elements 56 located in the aluminum body 84 of the block heater54 uniformly heat the fluid as it passes through the channel 78 acrossthe block heater 54. The channel 78 includes an outlet port 74 throughwhich heated fluid exits the channel 78 to the conduit 136. The heater54 is mounted within the handle assembly 16 via shafts 71 and plugs 73to bosses (not shown) in the handle assembly 16.

The size of the aluminum body 84 and the heating elements 56 areselected to effectively deliver approximately 500 watts of power to theheating block 54 to heat the cleaning fluid in the serpentine channel 78to a temperature of about 150-180 degrees. during the dry cycle of thecleaner and apply that heated cleaning fluid during the wet cycle, aswill be described more completely below. Use of approximately 500 wattsof power for the heater 54 leaves sufficient power from a convention 120volt power line for the vacuum motor, agitation brush and pump whileheating the solution to the target temperature with a minimal warm-uptime of approximately one minute. To enhance this process, hot tap water(defined as approximately 110-120 degrees Fahrenheit) can be dispensedinto the reservoir from a household tap. The solution that passesthrough the in-line block heater 54 is heated approximately 30 to 35degrees to reach a target temperature of approximately 150 degreesFahrenheit. A thermostatic controller is preferably mounted to a face ofthe heater 54 to limit the block temperature to 180 degrees Fahrenheit.In one embodiment, the solution that passes to the upholsteryattachments does not get the temperature boost. A non-heated solution isgenerally preferred for upholstery, which is more sensitive to heatdamage. Alternatively, both on-the-floor and above-the-floor cleaningoperations use heated cleaning fluid. In a further variation, theabove-the-floor tool selectively uses heated cleaning fluid in itscleaning operation. Of course, the heater is separately switched and canbe deactivated for non-heated operations.

Powered by approximately 500 watts, the in-line block heater 54 willboost the temperature of water 16 degrees Fahrenheit on a continuousbasis at 850 milliliters a minute. Since an approximately 30-degreetemperature increase is desired, it is necessary to store heat energy inthe aluminum body 84 of the in-line heater block 54 during the dry cycleand deliver it to the solution during the wet cycle. The recommendedcleaning process with the extraction cleaning machine 12 describedherein is two wet strokes, defined as movement of the extractioncleaning machine 12 while cleaning solution is sprayed from the nozzles100 to the carpet being cleaned, followed by two dry strokes, defined ascleaning solution and dirt removal through the suction action of thesuction nozzle 34. There is thus an opportunity to effectively deliver1000 watts of heat energy to the solution by storing 500 watts duringthe dry cycle. Furthermore, a typical cleaning stroke is about 10seconds maximum, so the heat reservoir must have the capacity to store500 watts for approximately 20 seconds, which equals approximately10,000 joules of energy. If a higher temperature was desired, forexample, up to 200 degrees Fahrenheit, a greater time period, forexample, 30 seconds, may be allowed or a larger block may be used toallow cleaning fluid to remain in the block longer.

The heating element 56 is embedded into the aluminum body 84, which isof ample mass to store the energy at some temperature below the boilingpoint of water (212 degrees Fahrenheit). The larger the mass ofaluminum, the smaller the differential temperature needs to be to storethe required energy. On the other hand, the larger the mass, the longerthe initial heat-up period becomes. The heater 54 according to theinvention heats the cleaning fluid to a temperature between 130 degreesand 180 degrees Fahrenheit, and preferably between 150 degrees and 180degrees Fahrenheit. There is an optimal size of aluminum block that iscalculated based on a thermostat shut-off point of 180 degreesFahrenheit. This block temperature keeps stagnant water from boiling andalso heats the solution that passes through the serpentine channels 78on the block face 76 to a temperature between 150 degrees and 180degrees Fahrenheit, and typically approximately 150 degrees Fahrenheitduring suggested use, before leaving the in-line block heater 54 throughoutlet port 74. In a preferred embodiment, it has been found that analuminum block having a size of about 3″ times 6.5″ times 1.25″ and amass of about 0.8 Kg. forms a suitable block for heating a solution tothe desired temperature of about 180 degrees Fahrenheit within about oneminute start up time and about 30 seconds during normal operation andfor storing about 10,000 joules of energy. The block is made with aserpentine channel essentially filling one face of the block for thesolution conduit and has an electrical resistance element of aserpentine configuration embedded in the block to continuously deliverabout 500 watts of electrical heating energy to the block.

In operation, when the heater 54 is initially energized electrically, itheats to its thermostatically controlled shut-off temperature inapproximately one minute. A temperature sensor or thermostat 92 isincluded on a lower face 108 of the body 84. During use, the cleaningsolution passes through the heating channel 78 in the in-line blockheater 54, drawing energy from the aluminum body 84 and from the heatingelement 56 embedded therein adjacent the underside of the solutionchannel 78. The aluminum body 84 cools somewhat during the 20 secondcycle and reaches a temperature slightly below its starting temperature.During the dry cycle, the aluminum body 84 is reheated to its previoustemperature of approximately 180 degrees Fahrenheit. The heated solutionleaving the in-line block heater 54 is applied to the carpet afterpassing through the conduit 136 to the flow indicator 650, and theconduit 134 from the indicator 650 to the fluid dispensing nozzles 100,which are positioned between the agitation brush 206 and the suctionnozzle 34.

In an alternative embodiment of the invention, a heater can be used toheat exhaust air from a fan directed to a fluid distributor in adischarge nozzle. For example, in U.S. Pat. No. 5,500,977 to McAllise etal., incorporated herein by reference, the cleaning solution distributoris position within the discharge nozzle and exhaust air from the fanexiting through the nozzle is divided into two airstreams, each disposedoppositely relative the fluid distributor. As the airstreams approachlips formed at the exit end of the discharge nozzle, the airstreams aredirected toward one another and converge immediately downstream of anexit opening of the discharge nozzle. Cleaning solution flows by gravityfrom the fluid supply tank and into the turbulent airflow created by theconverging airstreams exiting the discharge nozzle. According to oneembodiment of the invention, the airflow is heated by a heater includinga heating element disposed in the airstream, either before theairstreams are separated or while the airstreams separately traversealong opposite sides of the fluid distributor.

For this latter embodiment of the invention, the size of the heatingelements are selected to effectively heat the air, and thus the cleaningfluid, to a temperature between 130 and 180 degrees Fahrenheit. Again,use of approximately 500 watts of power for the heater leaves sufficientpower from a conventional 120 volt power line for the vacuum motor andagitation brush while heating the solution to the target temperaturewith a minimal warm-up time of approximately one minute to allow theheating element to reach operating temperature. To enhance this process,hot tap water (defined as approximately 110-120 degrees Fahrenheit) canbe dispensed into the fluid supply tank from a household tap. The fluidthat passes through the nozzle need only be heated approximately 10degrees to 30 degrees to reach a target temperature of approximately 150degrees Fahrenheit. A thermostatic controller is preferably mounted tothe heater to limit the heating element temperature to 180 degrees F.

The flow indicator 650 is placed in the fluid flow path to provide avisible indication of fluid flow to the fluid dispensing nozzles 100. Asshown in FIGS. 19 and 20, the flow indicator 650 is mounted to an upperend of the arm 651, which extends upwardly from the motor housing 500 inthe base module 14. An opening 653 in the upper housing portion 17receives the flow indicator 650 when that portion is mounted to thelower housing portion 15. Alternatively, the flow indicator 650 can bemounted to the handle assembly 16 in a position to be easily viewed bythe operator. The flow indicator 650 comprises a circular body 660having an inlet 652, outlet 654, and a clear lid 662 having a threadedlip 670. As seen in FIG. 20, the indicator body 660 preferably houses animpeller 664 superjacent a screen filter 666, both of which aresuperjacent the fluid inlet 652 and the fluid outlet 654. The fluidinlet 652 is near the periphery of the body 660 and the outlet 654 isdisposed centrally. The lid 662 has threads 670 on the outside of thebody 660.

The lid 662 is clear, preferably made from the transparent plastic, sothat the user can see the fluid flowing into the indicator 650 androtating the impeller 664. Alternatively, one or more articles, such asa ball or disk can be mounted within the indicator body 660 andsubjacent the lid 662, whereby the operator can determine if there isfluid flow by movement of the article. Further, while a body 660mounting an impeller 664 is the preferred flow indicator, other suitableindicators include a float ball, spring plunger, or gravity plunger.

A float ball-type flow indicator can include a flow conduit having aT-shaped portion having a transversely oriented tube extending from acylindrical body defining the fluid flow path. A ball or other articlecan be mounted at the junction of the transverse tube and cylindricalbody for reciprocation within the transverse tube. When fluid is flowingthrough the cylindrical body, the ball or article moves into thetransversely oriented tube, whereupon it is visible to the operator andindicates proper fluid flow.

A spring plunger-type flow indicator can include a light spring to biasa ball, plunger, or other article in a housing having a window visibleto the operator. With fluid flowing through the housing, the ball,plunger, or other article moves against the bias of the spring to becomevisible in the window, thereby indicating to the operator that fluid isflowing properly. Alternatively, the ball, plunger, or other article canalways be partially visible, and include portions corresponding toproper fluid flow, such as green for proper fluid flow and red for nofluid flow, whereby fluid flow causing movement of the ball, plunger, orother article against the spring bias would change the portion of theball, plunger, or other article visible to the operator through thewindow, thereby indicating proper fluid flow.

A gravity plunger-type flow indicator can include a housing having aball or other article mounted on a ramp adjacent a window. As fluidflows through the housing, the ball or other article is forced up theramp, whereby it is visible to the operator to indicate proper fluidflow. Alternatively, like that for the spring plunger, a portion of theball or other article previously not visible through the window can bevisible when fluid flows through the housing to indicate to the operatorthat fluid flow is proper.

After pressurized fluid leaves the in-line heater 54, it enters theinlet 652 of the flow indicator 650 under pressure, such that it causesthe impeller 664 to rotate in a clockwise direction as pictured in FIG.20. The fluid rotates the impeller 664 until it reaches the center ofthe body 660, where it is forced through the screen filter 666 andoutlet 654 by the continuous flow of pressurized fluid into the flowindicator body 660.

The screen filter 666 prevents any debris from exiting the flowindicator 650. Any debris trapped by the screen filter 666 remainsvisible to the operator through the lid 662. The operator can simplyclean the flow indicator 650 by removing the threaded lid 662 andlifting the screen filter 666 from within the body 660 for cleaning. Thescreen filter 666 preferably includes apertures defined by the screen ofa diameter smaller than the diameter a passageway through the spraynozzle 64. This is of particular importance if the spray nozzle is noteasily serviceable by the operator or a service provider. Further, whenusing an in-line heater 54, a screen filter 666 is a precaution againstplugging the passageway through the spray nozzle 64 from scales formingin the heater 54.

After the cleaning solution has been applied to the surface to becleaned via the spray nozzle 64, or multiple spray nozzles 64, the usedcleaning solution and entrapped dirt are removed from the surface beingcleaned through the suction nozzle 34, which opens into the firstworking air conduit 704 extending along the top of the base module 14between the upper housing portion 17 and the transparent facing 19, asbest shown in FIGS. 2, 12 and 13. The first working air conduit 704terminates at a junction 740 with the second working air conduit 706,which is defined by passageway communicating the vacuum source 40 withthe suction nozzle (not shown) on the distal end of the accessory hose22. With this configuration, the drive motor 196 creates the vacuumsource 40 that is applied to the surface being cleaned through eitherworking air conduit 704, 706.

The terminal end of the accessory hose 22 is secured to a hose mounting702 at a distal end of the accessory hose intake duct 540 partiallydefining the second working air conduit 706, which extends, in aU-shape, to the junction 740 with the working air conduit 704, as bestseen in FIGS. 1 and 12. A flapper valve 114 pivots at the junction 740,disposed in the base module 14, to alternatively close the first workingair conduit 704, between the suction nozzle 34 and the air/waterseparator lid 700, and the second working air conduit 706 between thehose mounting 702 and the air/water separator lid 700, as best shown inFIGS. 12 and 14. The valve 114 seats on a gasket 113 about the junction740. When the user is cleaning floors, the flapper valve 114 is inposition to direct all of the working air generated by the vacuum source40 to the suction nozzle 34. However, when the user desires to use theaccessory hose 22, the flapper valve 114 is pivoted to an accessory hoseposition, as shown in phantom lines in FIG. 12. In this position, theflapper valve 114 seals the working air conduit 704 and connects theaccessory hose 22 to the vacuum source 40. Regardless of whether themachine is operating for on-the-floor cleaning or accessory hosecleaning, all of the dirt and water recovered are directed into therecovery chamber 48.

An over-center diverter valve assembly 110 including a movable flappervalve 114 in the junction 740 between working air conduits 704, 706, andactuable by an actuator knob 180, on the extraction cleaner housingcontrols the diversion between the conduits 704, 706. More specifically,the actuator knob 180 to flapper valve 114 linkage assembly, as shownbest in FIGS. 12 and 13, includes an arm 160 attached at an upper end tothe flapper valve 114, which includes a transversely extending supportaxle 162, and at a lower end to a cup-shaped bearing 170 on the end of apiston 172. The support axle 162 is mounted for rotation in the junction740 between the working air conduits 704, 706, whereupon the valve canpivot between two extreme positions, as shown in FIG. 12. At a lowerend, the arm 160 ends in a transversely extending leg 164, which movesrelative the center of the actuator knob 180 depending on the positionof the actuator knob 180 when turned by the user.

The actuator knob 180 includes a handle 184, and a piston assembly 190on a back face. The piston assembly 190 includes piston housing 176,piston 172, and a compression spring 174. The piston 172 slidescoaxially in the housing 176, and is biased upwardly by the spring 174mounted therein. Specifically, the spring 174 biases the piston 172 outof an opening 196 in a top portion of a tubular piston housing 176.

When the actuator knob 180 is turned by the user, the lower leg 164moves closer or farther from the knob rotation axis, thereby increasingor decreasing the distance between the lower leg 164 and the axis. Asthis distance increases, the spring-biased piston 172 forces the lowerleg 164 upwardly. The arcuate path of the lower leg 164 as it travelsover the center of the knob axis rotation imparts rotation to theflapper valve 114 about the fixed support axle 162. The rotation is inresponse to the changed distance of the mounting of the piston assembly190 from the actuator knob 180 rotation center. As it moves away fromthe center, the piston 172 expands at an angle relative to the supportaxle 162. The lower leg 164 of the L-shaped arm 160 must rotate in thecup-shaped bearing 170 at the end of the piston 172 because the axle 162is fixed. Thus, the flapper valve 114 rotates in response to the angleof the joint between the expanded piston 172 and the lower leg 164 (notshown). Tabs formed on the back face of the knob 180 limit the rotationof the knob so as to effectively define two positions correlating to theopen conduit 704/closed conduit 706 position and the open conduit706/closed conduit 704 positions.

The diverter valve assembly 110 described above permits the uprightextraction cleaner fluid dispensing mechanism to be used as a pre-sprayapplicator. That is, by diverting the suction to the accessory hose 22,and applying solution through the fluid dispensing nozzles 100 adjacentthe agitation brush 206, the upright extraction cleaner 12 can be usedto dispense fluid and agitate the carpet without having the appliedsolution immediately extracted from the carpet through the suctionnozzle 34 adjacent the agitation brush 206 and fluid dispensing nozzles100. Thus, the fluid application system 950 remains operable regardlessof the position of the flapper valve 114.

As best seen in FIGS. 12-14, 14A and 14B, the working air conduit 704terminates at the junction 740 with the working air conduit 706. Thejunction 740 connects the selected conduit 704, 706 to a U-shaped inlet780 to the air/water separator lid 700, which is secured to the tankassembly 50 by the rotatable handle 790. Thus, from the U-shaped inlet780 to the air inlet 764, the air path entering the lid 700, as shown inFIG. 14, is substantially horizontal.

From the tank air inlet 764, the air/water/debris mixture is conductedinto a center portion of a tank lid separation chamber 750, where thecross-sectional area is greater than the flow conduits 704, 706,junction 740, and inlets 780, 764 to slow down the velocity of the airstream for gravity separation of the air from the liquid, dirt anddebris. Because the lid 700 is formed of a transparent plastic material,the user can easily observe the dirt and water passing up through theintermediate flow conduit and the fluid level inside the tank assembly50.

The substantially rectangular chamber 750 is defined by a transparentlower portion 752 substantially surrounded on all sides by a transparentside wall integral with the underside of the air/water separation lid700. The chamber 750 is further defined upwardly by a transparent face756 of the lid 700. The air inlet opening 764 is disposed adjacent anair outlet opening 764. The underside of the face 756 further includes acircular downwardly extending shroud 770 adapted to surround in part theopen flexible bladder filling spout 124, which is retained by the baffleplate 800 and positioned adjacent the separation chamber 750.

The working air flow enters the hollow interior of the separationchamber 750 via the air and water inlet 764 and passes horizontallybeneath the transparent face 756 to a rear wall defining a firstdiverter baffle 755 at which it is redirected 180 degrees forwardlythrough an opening 751 to a rectangular, extended outlet passage 757formed in a lower, intermediately disposed portion of the bottom wall752 at which it is again redirected 180 degrees by a second diverterbaffle 759 defined by a front wall disposed forward, transverse, andbeneath the opening 751. The air flow then exits the separation chamber750 through an inlet outlet 760, whose position is dictated by tankgeometry, as the preferred position is a “dead spot” in tank air flow tomaximize air/water separation. From here, the water is directed into theinterior of the tank between the 750 and the baffle 800, and away fromthe separation chamber 750 to the air exit 762. It is significant thatall air/water separation occurs above the baffle plate 800, thusminimizing interference with the recovered water (i.e., no foaming) inthe area disposed below the baffle plate 800. This characteristic isnecessitated by the inclusion of a flexible bladder disposed in the tankrecovery chamber.

In summary, air and water enters the inlet 764, from where it ischanneled to the air/water separation chamber 750 in which it strikesthe first diverter baffle 755, is redirected approximately 180 degreesand through the opening 751 to the outlet passage 757, where it is againredirected approximately 180 degrees by second diverter baffle 759, andthen passes into the interior of the recovery chamber 48. The multiplechanges in direction as well as the expansion in volume in theseparation chamber 750 facilitate the separation of water and debrisfrom the air. As best seen in FIG. 14, the air, free of water anddebris, exits the tank via rectangular outlet 762, and traverses ahorizontal conduit 774 to a vertical exit conduit 776, which is disposedadjacent the horizontal inlet 780 leading air into the separation lid700 via air inlet opening 764. Thus, the air inlet 780 and air exitconduit 776 are vertically adjacent. The air exit conduit 776 feeds theU-shaped conduit 540, which is connected to the vacuum source 40, asbest seen in FIGS. 1 and 14.

As best shown in FIG. 3, a fluid containment baffle 800 is mountedinside the hollow interior of the tank assembly 50 immediately below theseparation lid 700, and is intended to prevent the excessive sloshing ofthe recovered dirt and liquid and also contain any foam generated insidethe tank assembly 50. The planar baffle 800 comprises a flat body 810mated to snap fit within the tank housing 46. Further, apertures 820 areformed through the plate 800 for receiving the recovered fluid into therecovery chamber 48 of the tank assembly 50. A circular aperture 826retains the bladder filling spout 124 in position by preventing it fromfloating upwardly in the tank and further locking the bladder in placewhile giving it mechanical support.

The baffle plate 800 is snapped into place by retainers 830 that arereceived on tabs 836 formed on the interior of tank housing 46 to securethe baffle plate 800 in the tank assembly 50. The apertures arecentrally mounted in the baffle plate 800 to prevent air movement, whilefacilitating fluid and debris deposits, into a lower portion of tankassembly 50 so that the recovered fluid remains undisturbed. Further,the baffle plate 800 is closed at the edges to prevent sloshing of therecovered fluid into an upper portion of the tank assembly 50 duringmovement of the cleaning machine 12.

As shown best in FIGS. 14 and 14A, a float assembly 900 extends throughthe baffle plate 800 for moving an integral door across the exit port ofthe tank to prevent recovered solution from entering the tank exhaust inan overfill condition. As best shown in FIG. 3, the flag-shaped floatassembly 900 comprises a buoyant base 902 and a closure plate 904interconnected to one another by a support plate 906. The closure plate904 is dimensioned to fully seal an exit to the tank to preventrecovered solution from entering the tank exhaust in an overfillcondition. The closure plate 904 further includes a pair of triangularprojections 905 extending transversely from a substantially verticalfront face. The front face engages the wall 768 defining the air exit762 from the tank, and the projections 905 cam along that wall 768 toprevent premature and partial closing of the exit 762 as the plate 904is drawn against the exit by the suction therethrough.

The float assembly 900 is limited primarily to vertical movement withrespect to the tank assembly 50, with the closure plate 904 positionedabove the fluid containment baffle 800 and the buoyant base 902positioned below the baffle 800. A narrow slot 920 is provided in afront portion of the baffle 800 through which the support plate 906 ofthe float extends. Further, a housing 910 secured to the interior of thetank housing 46 guides the buoyant base, and thus the float assembly900, in a vertical direction. In the assembled position, the closureplate 904 is positioned above the baffle 800 and the buoyant base 902 ispositioned below the baffle 800.

As the recovered fluid within the tank assembly 50 rises, the floatassembly 900 will also rise until, eventually, the closure plate 904nears the tank exhaust exit opening, at which point the closure plate904 is sufficiently drawn against the exit 762 opening by the suctionfrom the vacuum motor to close the airflow therethrough. As discussedabove and illustrated in FIG. 14A, the triangular projection 905extending from the front face 907 ensure the closure plate is not drawnagainst the exit 762 prematurely, which would result in a partialclosure of the opening. Rather, the projections 905 ride the housingdefining the opening until drawn into total closure of the exit 762.Once this happens, the pitch of the operating vacuum changessufficiently to warn the user that the fluid recovery chamber 48 is fulland must be emptied.

As best shown in FIG. 3, a drain plug 850 seals an aperture through awall in a lower portion of the rigid housing 46 of the tank assembly 50through which recovered fluid can be removed without tipping the tankassembly 50, and also through which the tank assembly 50 can be cleanedby flow-through rinsing. More specifically, a rounded wall of the rigidtank housing 46 includes the drain plug 850 mounted in an aperture 854.A bottom portion of the aperture 854 is substantially planar with abottom wall 860 of the tank housing 46. Thus, any recovered fluid willflow through the aperture 854 when the drain plug 850 is removedtherefrom. Further, the tank assembly 50 can be cleaned without havingto tip the tank assembly 50 since the drain plug 850 can be removed forflow-through rinsing. This feature is particularly important because theflexible bladder 120 defining the fluid supply chamber 49 remains inplace while the recovered fluid is drained from the recovery chamber 48.The drain plug 850 eases cleaning of both the interior of the rigidhousing 46 and the exterior of the flexible bladder 120.

As best shown in FIGS. 21 and 22, the drain plug 850 comprises a knob851 extending through a circular washer 856 which mounts two resilientlegs 853. The resilient legs 853 are located diametrically on a lowerface of the washer 856 and comprise, on an outer face of each leg 853,an upper ridged protrusion 857 and a lower ridged protrusion 858. Thelower ridged protrusion 857 is rounded so that it forms a detentmechanism with the opening in the tank wall. The upper ridged protrusion857 has a slanted outer surface so that the legs are resilientlydeflected as the drain plug is installed into the aperture 854, and hasa sharp return inner surface so that the return inner surface will bearagainst the inner surface of the wall of the tank housing as the drainplug 850 is pulled outwardly of the tank. Thus, the drain plug is easilyinstalled into the aperture 854, but is retained therein by the innersurface when the plug is removed from the aperture 854 for draining thetank. In the normal, closed position of the drain plug 850, the lowerface of the washer 856 abuts the rear wall of the tank housing 46. Thedrain plug further has a pair of retaining flanges 859 which fit behindthe wall of the tank adjacent the aperture 854. To this end the aperturehas indented slots to receive the flanges 859. To drain fluid throughthe aperture 854, the drain plug 850 is rotated a quarter turncounterclockwise and pulled toward the rear of the upright extractioncleaning machine 12 a suitable distance such that the upper ridgedprotrusion 857 of the resilient legs 853 moves past the rear wall of thetank housing 46 and the lower ridged protrusion 858 of the resilientlegs 853 abuts the inner wall of the tank housing 46. The diameter ofthe aperture 854 is less than the normal distance between the resilientlegs 853 so that the legs 853 are pressed inwardly and thereby preventthe drain plug 850 from separating from the tank housing 46. The drainplug 850 is restored to its normal, closed position by pressing thedrain plug 850 toward the front of the upright extraction cleaningmachine 12 to cause the washer 856 to abut the rear of the tank housing46 and turning the drain plug 850 one-quarter turn clockwise.

In use, the operator removes the tank assembly 50 from the well 36 inthe base module 14, and further removes the lid 750 from the tankhousing 46 to expose the open filling spout 124 of the flexible bladder120, whereupon the bladder 120 can be filled with water from a sourcesuch as a household tap. Next, the user replaces the lid 750 and swingsthe handle 790 upwardly to seal the lid 750 to the tank housing 46,whereupon the tank assembly 50 can be carried to the well 36 of the basemodule 14 and replaced therein for use. Upon replacement, the valvemember 82 in the valve mechanism 80 mounted in the bottom surface 862 ofthe tank housing 46 is displaced by the projection 94 in the valve seat88, whereupon the clean water in the fluid supply chamber 49 is in fluidcommunication with the fluid application system 950. The detergentsupply tank 870 is removed from its well 884, and then its cap 880 isremoved so that the tank 870 can be filled with concentrated detergent.Once the supply tank 870 is filled and the cap 880 is replaced thereon,the supply tank 870 is replaced in its well 884, whereupon its valvemechanism 882 permits the flow of concentrated detergent through theconduit 318 to the mixing valve assembly 310.

The extraction cleaning machine 12 can then be powered by activating anmain power switch 534 disposed on the handle assembly 16, whereby themotor 196 is activated, and the vacuum source 40 for the working airflow conduits 704, 708 are operable. Further, the heater 54 isseparately operable by a heater power switch 536 when the main powerswitch 534 is in the “on” position. The user then supplies pressurizedcleaning solution to the agitation brush 206 by depressing the switch432 in the closed loop grip 18, whereupon solution flows to and throughthe fluid dispensing nozzles 100. As the user applies cleaning fluid andagitates the surface being cleaned with the brush 206, the user pushesthe cleaning machine 12 forward and rearward, with the forward strokesbeing defined as wet cycles and the rearward strokes being defined asdry cycles. During the wet cycles, the cleaning solution is applied tothe surface via the fluid dispensing nozzles 100 and the agitation brush206 scrubs the subjacent surface. During the dry cycles, the suctionnozzle 34 removes applied solution, as well as dirt and debris, from thesurface being cleaned and carries it to the recovery chamber 49 via theworking air conduit 704.

The cleaning machine 12 can also be used as a pre-spray applicator andagitator by simply diverting the air from working air conduit 704 to theworking air conduit 708, which connects the vacuum source 40 to theaccessory hose 22. In this use, the accessory hose 22 functions solelyas a bypass aperture for the working air supplied by the vacuum source40. Thus, fluid is applied via the fluid dispensing nozzles 100 andagitated into the surface being cleaned by the brush 206, but there isno suction at the suction nozzle 34, and thus no dry cycle. When thesolution has been adequately applied and the surface adequatelyagitated, the user can divert suction back to the working air conduit704, whereupon the applied solution and other debris can be removed fromthe surface without application of solution, which is controlled by theuser through trigger 432.

To use the accessory cleaning tool (not shown), the user diverts workingair flow from the conduit 704 to the conduit 708, whereupon theaccessory hose 22 is fluidly connected to the vacuum source 40.Furthermore, the user can apply pressurized cleaning fluid to thesurface to be cleaned by pressing the grip valve 132 on the accessorycleaning tool. In sum, cleaning solution can be applied by actuating thegrip valve 132 and removed via the suction nozzle (not shown) incommunication with the vacuum source 40 via the working conduit 708.Also, the accessory tool may further include an agitation brush drivenby an impeller that is driven by ambient air drawn through an aperturedistinct from the suction nozzle in the accessory tool, but towards thesame vacuum source 40.

Once the surfaces have been cleaned, or the recovery chamber 48 hasbecome filled and the float assembly 900 has blocked the air exit 762from the air/water separator lid 750, power to the cleaning machine 12is turned off and the tank assembly 50 is removed from the well in thebase module 14 and carried by its handle 790, which seals the lid 750 tothe tank housing 46, and carried to a point of disposal, such as a sinkdrain, whereupon the contents of the recovery chamber 48 can be emptiedby removing the drain plug 850 from the aperture 854 through wall 852.Once removed, the contents of the recovery chamber 48 flow through theaperture 854. Furthermore, the tank assembly 50 can be rinsed with cleanwater, which also flows through the aperture 854 in the wall 852 of thetank housing 46.

With reference now to FIG. 23, a cleaning wand according to a furtherembodiment of the invention includes a cleaning module 910 having anupper end that terminates in a handle assembly 912 and a lower end thatterminates in a nozzle assembly 914. An extension tube 916 extendsbetween the handle assembly 912 and the nozzle assembly 914. The nozzleassembly 914 includes an inner conduit 918 that extends between and isin fluid communication with a vacuum inlet 921 and the extension tube916. A working air flow path connected to a vacuum source is provided bya vacuum supply tube 922 attached to the handle assembly 912 and fluidlyconnected to the extension tube 916, conduit 918 and inlet 921 toprovide suction to a surface to be cleaned. Preferably, the vacuumsupply tube 922 is connected to a remotely located base module such as acanister-type carpet extraction cleaner 1217 having a motor and impellerfor creating the vacuum source as well as a pump for supplying cleaningfluid or water under pressure to the cleaning module 910 and a liquidrecovery tank for storing recovered fluid. This type of canister isdisclosed in U.S. Pat. No. 5,287,587, and therefore will not bedescribed in further detail.

A heater including a heating element 924 is located within the nozzleassembly 914 and includes a nozzle 926 that projects into a heated vapor(commonly heated vapor) chamber 928. The heated vapor chamber 928 isopen at a lower end 930 of the nozzle assembly 914 so that heated vaporprojected from the nozzle 926 can be applied to a surface to be cleaned.The heating element 924 is connected to a water tank (not shown) througha water delivery tube 932 and a water supply tube 948. The heatingelement receives power from the canister through electrical wires 934and generates heated vapor (steam) from the water in a well-knownmanner. A second water delivery tube 936 is arranged in the nozzleassembly 914 and is adapted to bypass the heating element 924 to therebysupply water directly to the surface to be cleaned. Preferably, a lowerend of the second supply tube 936 is connected to a spray nozzle 938 toevenly distribute cleaning fluid over a predefined area of the surfaceto cleaned. The water tank (not shown) which supplies fluid to theheating element 924 and the spray nozzle 928 can contain a cleaningsolution, if desired.

The water delivery tubes 932 and 936 are connected to a selector valve940 located within the handle assembly 912. A selector control knob 942(FIG. 23A) is attached to the selector valve 940 and is adjustablebetween a first normal position 944 for directing the cleaning waterfrom the supply tube 948 to the supply tube 936 and a second heatedvapor position 946 for directing cleaning water to the supply tube 932and into the heating element 924 for producing heated vapor. Asillustrated in FIG. 23B, the selector valve 940 comprises a pivotalvalve 962 that is pivotally mounted to a pivot pin 964 for movementbetween a fluid supply position shown in solid lines in FIG. 23B and aheated vapor supply position shown in phantom lines in FIG. 23B or to anin-between position (not shown) for delivery of both fluid and heatedvapor to a surface to be cleaned. The selector control valve 942 isdirectly linked to the pivot pin 964 to move the pivotal valve 962between the fluid supply position and the heated vapor supply position.An aqueous cleaning solution is preferably supplied to the selectorvalve 948 under pressure from a fluid pump (not shown) located on thecanister. A trigger 951 is accessible by a user in an opening 952 of thehandle assembly 912. The trigger 951 is pivotally attached to the handle912 through a pivot pin 954 and includes a finger 956 that is normallybiased against the supply tube 948 by a spring 958. The finger 956 in aclosed position pinches the tube 948 closed under biasing force of thespring 958. The biasing force is overcome when a user squeezes thetrigger 951 to thereby rotate the finger 956 out of contact with thetube 948 and opens the supply tube 948 so that water can flow to thevalve 940.

A pair of brushes 960 are mounted in the heated vapor chamber 928 andproject below the lower end 930 of the nozzle assembly 914 to therebyassist in loosening debris from the surface being cleaned.

With reference now to FIG. 24, a further embodiment of the invention isshown wherein like parts in the previous cleaning wand embodiment arerepresented by like numerals. This embodiment is similar to the previousembodiment with the exception that a cleaning module 911 including aselector valve 940 is positioned within the nozzle assembly 914. Acleaning fluid supply tube 949 is longer than the supply tube 948 in theprevious embodiment, while fluid delivery tubes 933, 937 are shorterthan the fluid delivery tubes 932, 936, respectively, in the previousembodiment. The selector control knob 942 is also positioned on thenozzle assembly 914 instead of the handle assembly for selecting betweennormal and heated vapor applications. With this embodiment, the entireheated vapor generating and selector unit can be supplied as a separateaccessory independent of the handle assembly 912.

In use, the vacuum hose 922, electrical wires 934 and supply tube 948,949 are connected to a base module such as a canister-type carpetextraction cleaner. Alternatively, the cleaning wand 910, 911 can formpart of a self-contained upright unit having cleaning solution and dirtywater tanks, a motor and impeller, liquid pump, etc. In any event,vacuuming can be performed by turning on the motor and impeller tocreate suction at the vacuum inlet 921 to thereby remove dry or wetdebris from the surface being cleaned without applying cleaningsolution. When it is desired to apply cleaning solution to the surface,the trigger 951 is squeezed with the selector control knob 942 in thenormal position 944. As the trigger is squeezed, liquid in the supplytube 948, 949 passes into the selector valve 940 and through thedelivery tube 936, 937 and out of the nozzle 938 onto the surface beingcleaned. When it is desired to apply heated vapor to the surface, theselector control knob 942 is rotated to the heated vapor position 946with or without pulling the trigger 951. Thus, heated vapor canselectively be applied to the surface for heating the surface to becleaned. Alternatively, the heated vapor can be applied to the surfaceto clean difficult spots while continuously squeezing the trigger 951.This feature provides a user with an option to alternate between heatedvapor and liquid without releasing the trigger 951. When the selectorcontrol knob is adjusted to the heated vapor position 946 and thetrigger 951 is pulled, cleaning liquid flows through the delivery line932, 933 and into the heating element 924 in which it is rapidly heatedinto heated vapor, projected out of nozzle 926, into heated vaporchamber 928, and onto the surface being cleaned. Any liquid on thesurface generated either by the heated vapor or the cleaning liquid iscollected at the vacuum inlet and deposited in a dirty solution tank(not shown) in the canister or upright.

Alternatively, a continuous delivery of heated vapor can be applied tothe surface to pre-heat the surface which, in turn, will heat anycleaning solution that might be applied at a later time to the extentthat the cleaning solution is at a lower temperature than thetemperature of the carpet or other surface to be cleaned. At the veryleast, the heated carpet will decrease any heat loss of a heatedcleaning solution that is applied to the carpet due to the elevatedtemperature of the solution as applied to the carpet. In yet anotherembodiment, the brush can be driven by a motor separate from the vacuummotor 196 and can be separately controlled so that they can be operatedindependently of the heated vapor generator. Furthermore, the vacuummotor 196 and the brush motor can be shut off, resulting in theapplication of heated vapor only. Removing the working air generated bythe vacuum motor 196 and additional air circulation created by therotating brush 216 results in higher surface temperatures which enhancecleaning.

With reference now to FIG. 25, a floor scrubber 1100 according toanother embodiment of the present invention includes a base module 1102and a handle assembly 1104 pivotally attached to the base module 1102.The base module 1102 includes a vacuum motor 1105 and impeller 1106attached to a shaft (not shown) of the motor for generating a vacuumsource. A nozzle 1108 is located at a forward end 1109 of the basemodule 1102 and is in fluid communication with the impeller 1106 forconnecting the vacuum source with the nozzle 1108. An elongate agitationbrush 1110 having radially extending bristles 1112 is connected to themotor shaft through a drive belt (not shown) or other well knownarrangement for rotating the agitation brush around its longitudinalaxis 1114. The base module 1102 also includes a pair of spaced-apartwheels II 5 (only one of which is shown) to facilitate manipulation ofthe floor scrubber along a surface.

A fluid supply tank 1116 is located at a rearward end 1118 of the basemodule 1102. A solution pump 1120 is fluidly connected to the fluidsupply tank 1116 through a hose 1122 that extends between an inlet port1123 of the pump 1120 and an outlet port 1125 of the fluid supply tank1116. The pump 1120 is preferably powered independently of the vacuummotor 1105 through appropriate electrical connections and a pump switch(not shown). Alternatively, the pump 1120 can be powered from the vacuummotor 1105 through a suitable transmission arrangement. A hose 1124extends between an outlet port 1127 of the pump and an inlet port 1128of a diverter valve 1126. The diverter valve 1126 includes a manuallyrotatable switch 1129 that diverts cleaning fluid under pressure fromthe hose 1124 to one of two outlet ports 1130, 1132. The switch 1129also includes electrical contacts (not shown) for turning on and off thevacuum motor 1105. The first outlet port 1130 is fluidly connected to adispensing nozzle 1134 via a hose 1136. The second outlet port 1132 isfluidly connected to a flash vapor generator 1138 via a hose 1140.

The handle assembly 1104 includes a trigger 1142 for selectivelyactivating the fluid pump 1120. An electrical cord holder 1144 isattached to a rearward portion of the handle assembly 1104.

Referring to FIG. 25A, an electrical schematic is shown of a controlcircuit for controlling the electrical energy to the vacuum motor 196and the heated vapor generator 1138. Electrical energy, typically in theform of 120 volt alternating current, is supplied to the extractorthrough line 1166 to a switch 1168 that is biased by spring 1170 to apole 1172 and alternatively can be pushed by switch 1129 to pole 1174.The pole 1172 is connected to the vapor heater 1138 though line 1176.The heated vapor generator is grounded through line 1178 and ground line1180. Pole 1174 is connected to vacuum motor 196 through line 1182.Vacuum motor 196 is grounded through line 1184 and ground 1180.

In use, fluid under pressure from the fluid supply tank 1116 is divertedto either the dispensing nozzle 1134 or the heated vapor generator 1138to alternatively apply cleaning fluid or heated vapor to a floor orother surface being cleaned depending on the position of switch 1129.When the switch 1129 is rotated to supply cleaning fluid to thedispensing nozzle 1134, the switch 1129 also turns on the vacuum motorand turns off the heated vapor generator 1138 through a mechanicalconnection to electrical switch 1168. The agitation brush rotates toloosen particles from the surface, and fluid along with any entraineddirt is then picked up by vacuum force at the nozzle 1108 and divertedto a recovery tank (not shown) in a well-known manner. Conversely, whenthe switch 1129 is rotated to a second position to supply cleaning fluidto the heated vapor generator 1138, the vacuum motor is automaticallyturned off through the connection to electrical switch 1168 and theheated vapor generator is simultaneously activated.

Although the switch 1168 is disclosed as controlled by switch 1129through a mechanical connection, the connection can be electrical. Inaddition, the switch 1168 can be electrically controlled by a thumbbutton switch 1186 on the handle assembly 1104 upper portion adjacent tothe trigger 1142.

Referring now to FIG. 26, a floor scrubber 1150 according to anotherembodiment of the invention is shown, wherein like parts in the previousfloor scrubber embodiment are represented by like numerals. The basemodule 1102 of the floor scrubber 1150 includes a heated vapor pump1152, a heated vapor nozzle 1154, and a liquid spray nozzle 1156. Theheated vapor pump 1152 has a pressure tank 1158 made of stainless steelor other material and a heater 1160. The heated vapor pump 1152 ispositioned in the rearward end 1118 of the base module 1102 and theheater 1160 is located adjacent to a lower portion of the tank 1158. Thepressure tank 1158 holds cleaning solution or other fluid. A hose 1162extends from an upper portion of the tank to the heated vapor dispensingnozzle 1154 and a hose 1164 extends from the lower portion of the tankto the liquid dispensing nozzle 1156. A pair of valves (not shown) ispreferably located at the upper and lower portions of the tank 1158, butcan be located at the heated vapor and spray dispensing nozzles 1152,1154, to selectively supply heated vapor or hot solution under pressureto the surface to be cleaned.

In operation, the heater 1160 heats the solution within the tank 1158 toapproximately 212 degrees F. (boiling point). With the valves closed,heated vapor is generated under pressure to a superheated state. Thegenerated heated vapor applies pressure to the hot solution and forcesthe solution to the surface to be cleaned when the hot solution valve isopened. Once in equilibrium, the volumetric flow of hot solution isreplaced by the same volume of generated heated vapor under the samepressure. The heated vapor thus serves as a hot solution delivery pumpto thereby eliminate a mechanical solution delivery pump. With the hotsolution valve closed and the heated vapor valve open, heated vapor issupplied under pressure to the surface to be cleaned. During surfacecleaning with heated vapor, the vacuum motor can be turned off or can beon. Although not illustrated, an agitation brush, like the agitationbrush 1110 shown in FIG. 25, can be provided and operated as the hotsolution is applied to the surface.

With reference now to FIG. 27, a floor scrubber 1200 according to yetanother embodiment of the invention is illustrated, wherein like partsin the previous floor scrubber embodiments are represented by likenumerals. The floor scrubber 1200 is very similar to the floor scrubber1100 in FIG. 25, with the exception that the heated vapor generator 1138is removed from the base unit 1102 and positioned in a hand-held hollowwand 1206.

The wand 1206 includes a grip portion 1208 and a nozzle portion 1210attached to an outer end 1211 of the grip portion. A flexible,corrugated vacuum hose 1212 is attached to an inner end 1214 of the gripportion 1208. The vacuum hose 1212 is fluidly connected to the impeller1106 for connecting a vacuum source to the nozzle portion 1210. Atrigger 1215 in the grip portion 1208 serves to both open a valve andprovide electrical power to the heated vapor generator 1138 in the wandwhen the trigger is pressed.

A supply hose 1216 extends between the diverter valve 1126 and heatedvapor generator 1138 to supply solution under pressure to the heaterwhen the pump is activated and the trigger is pressed. If desired, thetrigger 1215 may also serve as a switch for activating the pump.

In use, the heated vapor generator and pump are preferably activatedwith the vacuum motor turned off so that heated vapor can be applied topre-treat a surface to be cleaned. When the vacuum motor is turned on,the heated vapor generator is preferably turned off. Liquid solution canthen be applied either through the wand or through the spray nozzle 1134and then vacuumed up by the wand or nozzle 1108.

Reference is now made to FIG. 28 which shows a liquid delivery nozzleassembly section of an upright extractor which is disclosed in the U.S.Pat. No. 5,500,977 to McAllise et al. and is identical to the disclosurein the McAllise et al. U.S. Pat. No. 5,500,977 with the exception of aheat exchanger 1252 in the exhaust air conduit from the motor asdescribed below. Referring to FIG. 28, the liquid delivery nozzleassembly 1220 includes a liquid nozzle outlet opening 1224 at a forwardportion of the liquid delivery nozzle assembly section 1220. The nozzleassembly section comprises a top wall 1226, an intermediate wall 1228, asecond intermediate wall 1230 and a bottom wall 1232 which together formseparated heated air conduits 1242 and 1244 and a liquid supply channel1246. These conduits 1242, 1244 and the channel 1246 all meet at thenozzle opening 1244 to spray liquid cleaning solution onto an upholsteryor carpet surface as disclosed in the McAllise et al. U.S. Pat. No.5,500,977. A liquid delivery connector 1234 is connected to a liquiddelivery tube 1236 which is in turn connected to a liquid supply tank(not shown). A housing wall 1238 mounts the liquid delivery connector1234 and supports a motor having an impeller 1248 with an output openingwhich discharges pressurized air into a motor output duct 1250. Theforegoing is a disclosure of a nozzle assembly that is described ingreater detail and in connection with an upright extractor in theMcAllise et al. U.S. Pat. No. 5,500,977. The heat exchanger 1252 ispositioned in the motor output duct 1250 and is powered by electricalwiring 1254 for heating the air which passes from the motor output duct1250 and into the heated air conduits 1242 and 1244. This heated aircombines with the liquid from the liquid supply channel 1246 to heat theliquid which is dispensed from the nozzle opening 1224 and is depositedon a carpet surface in a manner disclosed in the McAllise et al. U.S.Pat. No. 5,500,977.

Referring now to FIG. 29, a floor scrubber 1170 according to anotherembodiment of the invention is shown, wherein like parts are used todescribe like numerals. The base module 1102 of the floor scrubber 1170includes a vapor generator 1172, a vapor nozzle 1154 and a vapor conduit1174. The vapor generator 1172 comprises a vessel 1158 made of stainlesssteel or other suitable non corrosive materials and a heater element1160. The heater element 1160 is preferably an electrical heatingelement but other heating elements can be used in lieu of an electricalheating element. In a preferred embodiment of the invention, water isused in the vapor generator 1172 to generate heated vapor. The vaporgenerator 1172 is positioned in the rearward end 1118 of the base module1102. A solution tank 1175 is also mounted at the rearward end 1118 ofbase module 1102 and has, at a lower end thereof, an outlet 1176connected to the inlet of a pump 1180. A solution conduit 1176 isconnected to the outlet of pump 1180, passes through the vapor conduit1174 in heat exchange relationship therewith and is connected at anotherend to a spray nozzle 1156. A valve 1182 is positioned between the inletto the vapor conduit 1174 and the outlet of the vapor generator 1172.The pump 1180 is connected to a source of electrical power through anelectrical circuit (not shown) which includes a switch (not shown) inthe handle for controlling the supply of electricity to the pump 1180.Further, the heater 1160 preferably comprises an electrical heatingelement which is connected in a circuit (not shown) to a switch (notshown) in the handle. A temperature sensor 1184 is mounted within thevapor generator 1172 to detect the temperature of the vapor therein. Thetemperature sensor 1182 is connected into a control circuit (not shown)within the electrical circuit for the heater element 1160 to open aswitch which connects the electrical energy to the heater element 1160when the temperature within the vapor generator 1172 reaches apredetermined level to prevent overheating of the vapor generator 1172.

The valve 1182 controls the opening between the vapor generator 1172 andthe vapor conduit 1174. The valve 1182 can take a number of forms,including a variable valve which is solenoid controlled to adjust thesize of the opening in the valve 1182 between the vapor generator 1172and the vapor conduit 1174. These valves are well known in the art ofvapor heating and generation. The valve can be electrically controlledin a circuit (not shown) which has a control knob or switch on thehandle 1104. In a preferred embodiment of the invention, water is placedin the vapor generator 1172 and heated vapor is generated in the vaporgenerator but other liquids can be used in the vapor generator in lieuof water in the vapor generator.

In operation, the electrical heating element 1160 is connected to thesupply of power to heat liquid in the vapor generator 1172 to produceheated vapor. The valve 1182 can be closed until such time as the heatedvapor reaches a predetermined temperature or pressure at which time itis opened to deliver vapor to the conduit 1174. When the vapor hassufficient pressure, it is sprayed onto the carpet or other surface tobe cleaned through the vapor nozzle 1154. The heated vapor released fromthe vapor nozzle 1154 contacts the surface to be cleaned and heats thesurface to be cleaned. Cleaning solution, which can include water or anaqueous detergent solution, fills the solution tank 1175. If it isdesired to spray the cleaning solution onto the carpet, a switch isoperated for the pump 1180 which begins to pump solution through theconduit 1178 in heat exchange with the vapor conduit 1174 and to thesolution spray nozzle 1156. The solution in the solution tank 1175 canbe sprayed onto the carpet, with or without heating by heat exchangewith the heated vapor and with or without spray of the heated vapor fromthe vapor spray nozzle 1154. In this case, the solution is heated afterbeing applied to the surface by a heat transfer from the surface causedby the heated vapor. Alternatively, the heated vapor can be sprayed ontothe carpet 1154 without spraying the solution from the spray nozzle1156. The vapor generator and the solution spray can operateindependently of each other so that the cleaning solution can be atambient temperature or above ambient temperature after being heated inheat exchange relationship with the vapor in the vapor conduit 1174.Further, the temperature of the vapor in the conduit 1174 can becontrolled by controlling the valve 1182 between the vapor generator1172 and the vapor conduit 1174.

Referring now to FIGS. 30 and 31, there is illustrated a ninthembodiment of the invention where like numerals are used to designatelike parts. An extraction cleaner 1300 has a base 1102 that is adaptedto move along a floor surface to be cleaned. A handle 1104 is pivotallymounted to the base 1102. A solution tank 1116 is mounted to a rearportion 1118 of the base 1102 and has a solution outlet 1122 which isconnected to the input 1123 of pump 1120. The output 1127 of pump 1120is connected to a solution conduit 1124 which splits in a Y to asolution conduit 1302 and a solution conduit 1314. Valves 1304 and 1316,respectively, are positioned in conduits 1302 and 1316 to control theflow of fluids through these conduits. Solution conduit 1302 isconnected to a heated vapor generator 1306 that has an electricalheating element 1308 positioned therein. A heated vapor conduit 1310 isconnected to an outlet of the heated vapor generator 1306 and extendsalong the front face of the base, terminating in a nozzle 1312 adjacentto the surface to be cleaned. The heated vapor conduit 1310 ispositioned on the front of the base 1102 so that the operator cancoordinate the heated vapor nozzle 1312 with spots on the floor thatneed particular cleaning.

A heated vapor button 1322 is positioned on the handle adjacent to atrigger 1142 for convenient operation with the thumb of a user. Thebutton 1322 is spring biased to an outward position so that the buttonsprings back when pressure is released on it.

As illustrated in FIG. 31, the button 1322 is connected to a switch 1344in an electrical system that includes power lines 1348 and 1350. Theswitch 1344 is connected in series with a solenoid coil 1346 whichoperates the opening and closing of the valve 1304. Thus, depression ofthe heated vapor valve button 1322 against the spring of the valve 1344closes the electrical circuit between lines 1348 and 1350 through coil1346 to open valve 1304. Solution then flows through the valve 1304 tothe heated vapor generator 1306 wherein it is vaporized with the heaterelement 1308 and is dispensed through the conduit 1312.

A thermal sensor 1334 is mounted in the heated vapor generator 1306adjacent to the heating element 1308. This thermal sensor 1334 isconnected through an electrical line 1352 to an induction coil 1338 in apower relay 1336. The power relay 1336 has pivotal switch element 1330that pivots between electrical contacts 1340 and 1342. Thermal switch1334 is set at a predetermined temperature to move the switch element1330 from contact 1342 to contact 1340, thereby resulting in currentflow between power line 1348 through electrical heating element 1308 topower line 1350. When the temperature rises to a second predeterminedlevel in the heated vapor generator 1306, then the coil 1338 releasesthe switch element 1330 to move to contact 1342, thereby resulting incurrent flow between power line 1348 and 1350 through the electricalheating element 1320. Thus, thermal switch 1334 controls the temperaturein the heated vapor generator 1306 between predetermined points,preferably around 220° Fahrenheit. For example, the switch can open at225° F. and close at 215° F. degrees.

In operation, the trigger 1142 operates the flow of solution through thepump 1120. Cleaning solution can flow continuously or intermittentlythrough the solution heater 1318 and dispense heated cleaning fluid ontothe surface to be cleaned through the spray nozzle 1134. When it isdesirable to clean a spot on the floor that is particularly soiled, theuser presses the thumb button 1322 to open the valve 1304 and generatesheated vapor within the heated vapor generator 1306. Heated vapor willbe dispensed through the heated vapor nozzle 1312 onto the floor surfacein full view of the operator who is able to control the amount of heatedvapor as well as the location of the heated vapor on the surface to becleaned.

Referring now to FIG. 32, there is shown in an alternate embodiment of aheated vapor generator and a solution heater, which are combined into asingle alternate heated vapor generator 1352. In this drawing, likenumbers have been used to designate like parts. The elements of heatedvapor generator 1306 are essentially the same as in the embodiment ofFIG. 32 but the solution conduit 1314 has a heat exchange coil 1354 thatextends through the alternate heated vapor generator 1352. Cleaningsolution within the coil 1354 is heated by radiant energy from theelectrical heating element 1308 and, in addition, by conduction throughheated vapor which is generated from time to time in alternate heatedvapor generator 1352.

Preferably, the heat exchange conduit 1354 is wound around theelectrical heating element 1308 or it can coiled directly above theheating element 1308. In any case, the cleaning solution sprayed intothe heated vapor generator 1306 is vaporized by the electrical heatingelement 1308 to generate heated vapor as described in the embodiment ofFIGS. 30 and 31.

While particular embodiments of the invention have been shown, theinvention is not limited thereto since modifications may be made bythose skilled in the art, particularly in light of the foregoingteachings. Reasonable variation and modification are possible within thescope of the foregoing disclosure of the invention without departingfrom the spirit of the invention which is defined in the appendedclaims.

1. A surface cleaning apparatus, comprising: a heated vapor generatoradapted to heat fluid to approximately 212° F. to generate steam; asupply tank for containing a supply of fluid; a vapor nozzle configuredto dispense steam to the surface to be cleaned; a liquid spray nozzleconfigured to dispense liquid to a surface to be cleaned; a vaporconduit in fluid communication with the heated vapor generator and thevapor nozzle; and a liquid conduit in fluid communication with thesupply tank and the liquid spray nozzle, wherein a portion of the liquidconduit is in heat exchange relationship with the vapor conduit.
 2. Thesurface cleaning apparatus of claim 1, wherein the heated vaporgenerator comprises a vessel and a heater element within the vessel. 3.The surface cleaning apparatus of claim 1, and further comprising avalve positioned between an inlet to the vapor conduit and an outlet ofthe heated vapor generator.
 4. The surface cleaning apparatus of claim3, and further comprising a pump positioned between an outlet of thesupply tank and the portion of the liquid conduit in heat exchangerelationship with the vapor conduit.
 5. The surface cleaning apparatusof claim 3, and further comprising a temperature sensor within theheated vapor generator to detect the temperature of the vapor therein.6. The surface cleaning apparatus of claim 3, and further comprising apump fluidly coupled to the supply tank, wherein the pump is operableindependently of the heated vapor generator.
 7. The surface cleaningapparatus of claim 1, and further comprising a vacuum source forgenerating a vacuum force and a suction nozzle in fluid communicationwith the vacuum source.
 8. The surface cleaning apparatus of claim 7,wherein the heated vapor generator is operable independently of thevacuum source.
 9. The surface cleaning apparatus of claim 1, wherein thesurface cleaning apparatus comprises an upright unit including a basemodule and a handle assembly pivotally attached to the base module,wherein the vapor nozzle and the liquid spray nozzle are provided on thebase module.
 10. The surface cleaning apparatus of claim 9, wherein thebase module further comprises the heated vapor generator and the vaporconduit.
 11. The surface cleaning apparatus of claim 9, wherein the basemodule further comprises the supply tank and the liquid conduit.
 12. Thesurface cleaning apparatus of claim 11, wherein the heated vaporgenerator is located above the supply tank.
 13. The surface cleaningapparatus of claim 9, wherein the base module comprises a suction nozzlein fluid communication with a vacuum source.
 14. The surface cleaningapparatus of claim 13, wherein the vapor nozzle and the liquid spraynozzle are provided with the suction nozzle.
 15. The surface cleaningapparatus of claim 13, wherein the vapor nozzle and the liquid spraynozzle comprise respective outlets provided within the suction nozzle.16. The surface cleaning apparatus of claim 13, wherein the suctionnozzle is located at a forward end of the base module.
 17. The surfacecleaning apparatus of claim 16, wherein the heated vapor generator andthe supply tank are stacked at a rearward end of the base module. 18.The surface cleaning apparatus of claim 1, wherein the portion of theliquid conduit in heat exchange relationship with the vapor conduit islocated within the vapor conduit.
 19. The surface cleaning apparatus ofclaim 18, wherein a portion of the liquid conduit distal to the portionof the liquid conduit in heat exchange relationship with the vaporconduit is located exteriorly of the vapor conduit.
 20. The surfacecleaning apparatus of claim 19, wherein the liquid spray nozzle islocated exteriorly of the vapor conduit.